Abstract

In this study, the incorporation of surface plasmon resonance (SPR) spectroscopy with novel chitosan-graphene oxide/cadmium sulphide quantum dots (CdS QDs) active layer for cobalt ion (Co2+) detection has been developed. The interaction of different Co2+ concentrations with the novel modified active layer was monitored using the SPR technique. From the SPR results, detection range, sensitivity, full width at half maximum (FWHM), detection accuracy (DA) and signal-to-noise ratio (SNR) have been analysed. The results showed the detection range of this optical sensor was 0.01 to 10 ppm, and it was saturated for higher concentration of Co2+. The sensitivity obtained was 0.1188 ppm−1 for low concentration of Co2+ ranged from 0.01 to 1 ppm. The FWHM and DA were consistent for all concentration of Co2+, while the SNR of the SPR signal increased with the Co2+ concentration. The SPR angle shifts were also fitted using Langmuir, Freundlich and Sips (Langmuir-Freundlich) isotherm models, where Sips model fitted the best with the binding affinity of 0.939 ppm−1. The results proved that the novel chitosan-graphene oxide/CdS QDs modified gold thin film can detect Co2+ via SPR spectroscopy.

© 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Corrections

5 November 2019: A typographical correction was made to the author listing.

1. Introduction

Cobalt is a naturally occurring element with one stable isotope which is 59Co with three valence states namely 0, +2, and + 3; however, Co2+ is more stable than Co3+. Cobalt is said to be the 33rd most abundant element which can be found in a variety of media such as water, air, groundwater, soil, hazardous waste site, and sediment [1,2]. Observed from its reputation as one of the most abundant elements, cobalt is broadly used in industrial and commercial applications. Cobalt was once primarily used in the production of super-alloys for many mechanical parts. It was also popularly used as pigment and colouring before the 19th century [3]. Nowadays, it is vastly used in the production of battery electrodes for rechargeable batteries due to the rapid growth of the rechargeable battery industry [4]. Apart from that, cobalt is an essential component of vitamin B12 which is important for the metabolism of all living creatures [5]. However, consumption at high dose and long-term exposure of cobalt ion may pose adverse health effects [68]. Due to that, a lot of effort have been poured into the development of techniques and method for the determination of Co2+ [913].

In recent years, optical sensors have been acknowledged as one of the techniques applied for the detection of targeted elements due to their good performance for a wide range of samples analysis, easy handling, and fast detection. Surface plasmon resonance (SPR) spectroscopy is an exceptionally versatile label-free optical sensor that has been developed for sensing a wide range of target samples such as for biosensor [1421] and metal ions [2226]. The surface plasmon resonance phenomenon occurs when the energy from an electromagnetic wave such as laser interacts with the free electrons on the metal-dielectric interface. The vibration of electrons at the interface due to the absorption of energy is called surface plasmons [27]. Resonance angle may occur at a specific angle where the intensity of the reflected light decreases, producing a sharp dip of intensity due to the resonance energy that occurs between the incident beam and the surface plasmon wave (from metal) [2729]. However, the performance of metal layer such as gold, silver or platinum as a sensing layer is not sensitive enough [3032].

In order to improve the performance and response of the sensor, the gold layer needs to be modified with a suitable novel layer. The most common material used as the sensor layer is polymer or conductive polymer [25,33]. As such, chitosan is one of the polymers that has been commonly used in recent years [3436]. Chitosan is a versatile material that can be used to prepare hydrogels, films, fibres and has good absorption properties. Due to that, chitosan has been used as a base material for many applications [3739]. In this project, chitosan was used as the base material to fabricate a composite thin film. In order to improve the sensitivity of the SPR sensor for the detection of cobalt ion, some modification on the chitosan has been further explored. Graphene oxide (GO) was used to reinforce the composite thin film which may contribute to the increase of the absorption properties of the thin film [40,41]. Cadmium sulphide quantum dots (CdS QDs) are one of the quantum dots family and they are unique due to their nano-size particles. Some studies have been conducted for metal ion sensing using CdS QDs material [4244]. However, most of the studies reported that CdS QDs was used in the fluorescence sensor and as far as concerned, there is still no study on the metal sensing application of CdS QDs using the SPR technique. Therefore in this study, the performance of the novel modified thin film to detect Co2+ was investigated and analysed. The binding modulation of the sensor layer was also investigated by fitting the results to the Langmuir, Freundlich and Sips (Langmuir-Freundlich) isotherm models.

2. Materials and method

2.1 Reagent and materials

Medium molecular weight (MMW) chitosan with MW of 190,000-310,000 and degree of deacetylation of 75-85% and acetic acid (assay ≥ 99.7%) were purchased from Sigma Aldrich (St. Louis, MO, USA). Cadmium chloride dihydrate (CdCl2.10H2O), Mercaptoacetic acid (MPA) (HS-CH2-COOH) and disodium sulphide nonahydrate (Na2S·9H2O) were purchased from R&M chemicals. GO (4 mg/mL) was purchased from Graphenea (Cambridge, MA, USA).

2.2 Preparation of chitosan-GO/CdS QDs modified gold active layer

For the preparation of active layer, glass cover slips (24 mm × 24 mm × 0.1 mm, Menzel-Glaser, Germany) were cleaned and first deposited with a thin gold layer using an SC7640 sputter coater. The chitosan-GO/CdS QDs solution was first prepared before the gold surface was modified.

The CdS Qds were prepared by a simple wet process. It started by dissolving 0.5 mmol of MPA and 0.5 mmol of CdCl2⋅10H2O by adding 250 ml of ddH2O water in a 500 ml beaker. The pH of the solution was adjusted to 6.0 by adding 1 M NaOH solution dropwise with constant stirring. Subsequently, the solution was purged with nitrogen gas for at least 60 min under vigorous stirring. Then, 0.5 mmol of Na2S⋅9H2O was added dropwise into the stirred solution until the clear yellowish suspension of CdS QDs was obtained. The obtained aqueous CdS QDs were then quenched at 0°C in the freezer (45 min) and stored in a refrigerator at 4°C [45,46]. The chitosan solution was prepared by dissolving 0.4 g of MMW chitosan with 50 ml of 1% acetic acid. A composite solution with a 1:1:1 ratio was prepared by stirring 10 ml of chitosan, GO and CdS QDs solution for 1 hour and then sonicated again for another hour.

The glass cover slips with gold surface were treated with modification using using the spin-coating technique (Specialty Coating System, P-6708D). About 0.55 ml of the composite solution was dropped on the gold layer, covering the majority of the surface [47]. The glass cover slip was spun at 4000 rev/min for 30 s to produce the composite thin film. The thickness of the gold layer and the gold/active layer was determined by using high surface stylus profilemeter (AMBIOS XP-200) where the thickness of gold layer and gold/chitosan-GO/CdS GQs active layer are 47 nm and 73 nm, respectively.

2.3 Surface plasmon resonance technique

The SPR measurements were carried out using a custom-built instrument set up as shown in Fig. 1. As shown in the figure, the He-Ne laser (λ = 632.8 nm) that was p-polarised gave out only the transverse mode (TM) of the laser to propagate through a prism (refractive index, n = 1.77861 at 632.8 nm). The glass cover slip attached to one side of the prism using a refractive index matching liquid with a hollow cell was attached to the gold or gold/chitosan-GO/CdS QDs film surface containing the Co2+ solution. The prism and the hollow cell were mounted on a rotating plate to control the angle of the incident light. The rotating plate was driven by a stepper motor with a resolution of 0.001° (Newport MM3000). The He-Ne laser beam that was incident on to the prism passed through the sample (derivative thin film), and the reflected beam was detected by a large area photodiode where the signal was then processed by the lock-in amplifier (SR 530) [35].

 figure: Fig. 1.

Fig. 1. Schematic diagram of surface plasmon resonance spectroscopy.

Download Full Size | PPT Slide | PDF

3. Results and discussion

3.1 SPR responses of gold thin film in contact with Co2+

Firstly, SPR test was carried out using gold film in contact with deionised water as an initial test [47]. Approximately 2 ml of deionised water was injected into the hollow cell in contact with the gold film. The measurement was run and the SPR reflectivity curve for gold film with thickness of 47 nm in contact with deionised water was then plotted as shown in Fig. 2.

 figure: Fig. 2.

Fig. 2. SPR curve of gold film in contact with deionized water.

Download Full Size | PPT Slide | PDF

From the SPR curve, the resonance angle was obtained at 53.634°. Then, the SPR experiment was carried out with different concentrations of Co2+ ranging from 0.01 ppm to 100 ppm. The Co2+ aqueous solutions were injected one after another into the hollow cell. The SPR reflectivity curves of Co2+ were obtained and compared with the reflectivity curves of deionised water. Thus, the SPR curves ranging from 0 to 100 ppm in contact with the gold film are shown in Fig. 3.

 figure: Fig. 3.

Fig. 3. SPR curves of gold film in contact with different concentration of Co2+ (0 to 100 ppm).

Download Full Size | PPT Slide | PDF

The resonance angle of all concentrations of Co2+ was observed to be the same as the resonance angle of the deionised water which was approximately 53.634°. This result may be due to the inability of the gold film only to absorb Co2+ or metal ions as reported by other researchers [9,44]. In addition, the shift of resonance angle depends on the changes of refractive index adjacent to the metal layer. Previous study shows that the refractive index of lower concentration of metal ion are similar which further confirmed the result [48]. Therefore, the gold surface has to be modified with an active layer to increase the changes of refractive index asjacent to the gold surface and hence the sensitivity of the sensor.

3.2 SPR responses of modified gold active layer in contact with Co2+

Due to the inability of the gold layer to sense the lower concentration of cobalt ion, the experiment was then continued by replacing the gold film with gold/chitosan-GO/CdS QDs active layer. The experiment was repeated first with deionised water in contact with the active layer. The SPR reflectivity curve of the active layer in contact with deionised water is shown in Fig. 4.

 figure: Fig. 4.

Fig. 4. SPR curve of gold/chitosan-GO/CdS QDs active layer in contact with deionized water.

Download Full Size | PPT Slide | PDF

The modification on the gold layer causes the resonance angle to be shifted to the right from 53.634° to 53.841° when in contact with deionized water. This can be explained by changes the refractive index of the material adjacent to the metal layer. The experiment was then further carried out with different concentrations of Co2+ in the range of 0.01 ppm to 100 ppm. The Co2+ solution was injected one after another into the hollow cell. Each injection was left for 2 minutes before the SPR curve of the sample was taken in order to have a maximum interaction between the metal ion with the active layer and this experiment was repeated three times to observe the accuracy of the data. The SPR reflectivity curves for the Co2+ concentration of 0 to 100 ppm were then plotted as shown in Fig. 5.

 figure: Fig. 5.

Fig. 5. SPR curves of gold/chitosan-GO/CdS QDs active layer in contact with different concentration of Co2+ (0 to 100 ppm).

Download Full Size | PPT Slide | PDF

The resonance angles determined from the SPR curves were 53.841°, 53.854°, 53.934°, 53.952°, 53.984°, 54.025°, 54.039°, 54.043°, 54.042°, 54.045°, and 54.057° for Co2+ concentration of 0, 0.01, 0.1, 1, 5, 10, 20, 40, 60, 80 and 100 ppm, respectively. It can be seen from the result that there was a significant shift of the resonance angle as the concentration of the Co2+ was increased. This finding can be attributed to the binding between the active layer composite thin film and the Co2+, which led to the increase of refractive index of the sensing layer and thus causing the higher shift of resonance angle [49,50]. In addition, the shift of the resonance angle at 0.01 ppm indicate that this active layer can detect Co2+ ion at concentration as low as 0.01 ppm or 10 ppb. Table 1 presents the comparison of this study, i.e. gold/chitosan-GO/CdS QDs via SPR sensor for the detection of Co2+ with previous reported method. From the table, it shows that this study does have the upper hand on the limit of detection as compared to the previous reports.

Tables Icon

Table 1. Comparison of gold/chitosan-GO/CdS QDs active layer via SPR method for the detection of Co2+ with previous reports.

3.3 Sensitivity and linearity range

The sensitivity of this sensor can be determined by plotting the resonance angle shift against the concentration of Co2+ as shown in Fig. 6. Overall, it can be seen that the composite thin film active layer displayed great sensitivity towards Co2+ up to 10 ppm. The sensitivity of the active layer towards Co2+ with concentration higher than 10 ppm was lower and may reach a saturated value at 20 ppm that may due to the congestion of Co2+ on the active layer surface. For further analysis, the plotted data were fitted linearly. To obtain the best linear regression coefficient R2, three different regions was fitted separately, as shown in Fig. 6.

 figure: Fig. 6.

Fig. 6. SPR angle shift against Co2+ concentration.

Download Full Size | PPT Slide | PDF

The R2 for the first region (0 to 1 ppm) was 0.64 and the relationship between the SPR angle shift (ΔθSPR) and the Co2+ concentration was governed by the Eq. ΔθSPR = 0.1188[Co2+] + 0. The second region, R2 was 0.99 and ΔθSPR = 0.0081[Co2+] + 0.1024 for 1 to 10 ppm. Lastly, the R2 and ΔθSPR for 10 to 100 ppm were 0.77 and ΔθSPR = 0.00026[Co2+] + 0.1870, respectively. The gradient of the linear regression plotting can be defined as the sensitivity of the active layer towards the Co2+ [55,56]. The linear regression plotting yielded gradients of 0.1188° ppm−1, 0.0081° ppm−1 and 0.00026° ppm−1 for the first, second and the third region, accordingly. This concluded that the active layer was sensitive towards Co2+ and exhibited more sensitivity for lower concentration of the ion.

3.4 SPR data analysis parameter

By analysing the SPR curve and data, some important parameters including the full width at half maximum (FWHM), detection accuracy (DA) and signal-to-noise ratio (SNR) can be determined. The DA of resonance angle depends on the width of the SPR curve. The narrower the SPR curve, the higher the DA. The DA is inversely proportional to the FWHM of the SPR reflectivity, where the FWHM can be defined as the angular width for the half value of the maximum SPR reflectivity curve [57]. FWHM can be determined by measuring the width of the reflectivity curve corresponding to the half value of the maximum reflectance as shown in Fig. 7. All the calculated values of the FWHM and DA of the gold/chitosan-GO/CdS QDs-based SPR sensor upon adsorption of Co2+ are summarized in Table 2.

 figure: Fig. 7.

Fig. 7. The FWHM of SPR curve corresponding to half from its maximum value.

Download Full Size | PPT Slide | PDF

Tables Icon

Table 2. Values of FWHM and DA of different concentration of Co2+.

From the table, it can be concluded that lower concentration of Co2+ (20 ppm and below) has the narrowest FWHM and highest DA. However, there is no obvious trend observed for the FWHM and the DA where most of the values of FWHM are around 2.79° to 2.96° and 0.338/° to 0.358/° for the DA. The DA of this SPR sensor towards Co2+ is shown in Fig. 8. It can be observed that there is no major effect of the different concentrations of Co2+ on the DA of this sensor as the width of the SPR reflectivity curves are almost the same, only the positions of the resonance angle are varies.

 figure: Fig. 8.

Fig. 8. Detection accuracy of the chitosan-GO/CdS QDs based SPR sensor towards Co2+.

Download Full Size | PPT Slide | PDF

The SNR is another performance parameter of SPR sensor apart from the sensitivity. The SNR of an SPR sensor depends on how accurate and precise the sensor can detect the resonance angle, on the other way the refractive index of the sensing layer. The SNR on an SPR sensor was determined by multiplying the SPR angle shift, ΔθSPR by detection accuracy, DA [58]. Hence, the SNR of SPR sensor can be expressed as:

$$SNR = \frac{{\Delta {\theta _{SPR}}}}{{FWHM}} = \Delta {\theta _{SPR}} \ast DA$$
The SNR of the gold/chitosan-GO SPR sensor in contact with different concentrations of Co2+ is represented in Fig. 9. It can be distinguished that even with the little variation of the DA, the SNR still increased with the increment of Co2+ concentration. This can also conclude that SNR is an indicator of binding affinity due to the dependency of the ΔθSPR. In addition, it can clearly be observed that the SNR plotting in Fig. 9 is almost similar to the plotting of shifts in the SPR angle in Fig. 6. This showed that the ΔθSPR has a greater effect compared to the DA in determining the SNR value [57].

 figure: Fig. 9.

Fig. 9. Signal-to-noise ratio of the chitosan-GO/CdS QDs based SPR sensor towards Co2+.

Download Full Size | PPT Slide | PDF

3.5 Association studies via equilibrium isotherms

Equilibrium isotherm Eqs. were used to portray the experimental sorption data [57]. These equilibrium models may give some insight about the sorption mechanism and the surface properties and also the affinity of the sorbent. Langmuir isotherm and Freundlich isotherm are two of the most widely used analytical isotherms for adsorption studies to obtain the binding model of metal ion and the sensor layer [56,59,60]. Freundlich isotherm is the earliest known sorption isotherm Eq. presented by Freundlich in 1906 [61]. This isotherm has been derived by assuming an exponentially decaying sorption site energy distribution. The Freundlich Eq. that was used to describe the heterogeneous surface energy can be expressed as:

$$\Delta {\theta _{sat}} = {K_f}{C^n}$$
Where Kf is a Freundlich constant which is an affinity constant, C is the concentration of the Co2+ and n is the heterogeneity index [61].

Langmuir model on the other hand, is based on the assumption of a stronger adsorption energy for the first layer of adsorbed molecules in a homogenous system without interaction between adsorbed molecules [62]. According to the Langmuir theory, the saturated monolayer isotherm for metal ion adsorption on sensor surface can be expressed as:

$$\Delta {\theta _{sat}} = {\frac{{\Delta {\theta _{max}}{K_L}C}}{{1 + {K_L}C}}^{}}$$
Where Δθmax is the maximum of the resonance angle shift, KL is the Langmuir constant which is an affinity constant, C is the concentration of the Co2+ and n is the heterogeneity index [58].

While the Langmuir-Freundlich isotherm or also known as Sips Eq. is a versatile isotherm expression that can simulate both Langmuir and Freundlich behaviours [63]. Sips isotherm is a combination of both Langmuir and Freundlich expressions which is able to predict the heterogeneous adsorption system and overcome the limitation of the rising adsorbate concentration associated with the Freundlich isotherm model. Generally, the Eq. parameters are influenced mainly by the operating conditions such as the alteration of concentration, pH, and temperature [64]. By combining both Langmuir and Freundlich Eqs. in Eq. 2 and 3, the Sips Eq. can be expressed as:

$$\Delta {\theta _{sat}} = \frac{{\Delta {\theta _{max}}{{({K_s}C)}^n}}}{{1 + {{({K_s}C)}^n}}}$$
Where Ks is the Sips constant or the affinity constant, C is the concentration of the Co2+, and n is the heterogeniety index [65]. By using Sips isotherm model, one can vary the density function for heterogeneous systems using the heterogeniety index n, which can be varied from 0 to 1. For a homogenous material, the value of n is 1 and for heterogeneous material, the value of n is less than 1.

In this study, the adsorption data were fitted to Langmuir, Freundlich and Sips models using the Origin programme to obtain the binding model of Co2+ with CdS QD-chitosan-GO composite thin film. These equilibrium isotherm models fitting are shown in Fig. 10. The comparison of fitted values of Langmuir, Freundlich, and Sips parameters for Co2+ adsorption on gold/chitosan-GO/CdS QDs composite layer is shown in Table 3. All three models were well-fitted with high value of correalation coefficient, R2, where Sips fitting showed the highest R2 value with 0.96716, followed by Freundlich and Langmuir with 0.93708 and 0.89355, respectively. From the table, it can be observed that the maximum resonance angle shift of the Sips model was closer to the experimental maximum resonance angle shift, i.e. 0.2159°, as compared to the maximum resonance angle shift of Langmuir model fitting. This proved that the Sips model was fitted better to the experimental data which may lower the significant errors of the parameters [59]. From the Sips model, the affinity constant or the binding affinity of the Co2+ towards gold/chitosan-GO/CdS QDs active layer was 0.939 ppm−1. Overall, the results obtained proved that the the gold/chitosan-GO/CdS QDs active layer has high potential as a SPR sensing layer for determining Co2+.

 figure: Fig. 10.

Fig. 10. Equilibrium isotherm models fitting for the resonance angle shift of Co2+ in contact with gold/chitosan-GO/CdS Qds active layer and gold thin film.

Download Full Size | PPT Slide | PDF

Tables Icon

Table 3. Fitted values of Freundlich, Langmuir and Sips parameters for the adsorption of Co2+ on the gold/chitosan-GO/CdS QDs active layer.

4. Conclusion

In this present work, novel chitosan-graphene oxide/CdS QDs modified gold active layer has been successfully fabricated to provide an enhanced evanescent field onto the SPR sensor for the determination of Co2+. The performance of the sensor layer has been investigated by observing the resonance angle shift of the SPR curves with increasing Co2+ concentration. The result revealed that the introduction of the novel active layer produced a good response towards the Co2+ solution with a sensitivity of 0.1188 °ppm−1 for lower concentration from 0.01 ppm to 1 ppm, 0.0081 °ppm−1 for the concentration from 1 ppm to 10 ppm, and 0.0004 °ppm−1 for highr concentration of 10 ppm to 100 ppm, with high detection accuracy, i.e. 0.338/° to 0.358/°. In addition, the signal-to-noise-ratio result shows a similar trend with the data plot of resonance angle shift against Co2+ concentration. Lastly, the experimental results obtained were modeled using Langmuir, Freundlich, and Sips (Langmuir-Freundlich) isotherm Eqs. It is found that Sips isotherm model fitted well with the experimental data to produce R2 value of 0.96716 with high affinity constant, i.e. 0.939 ppm−1.

Funding

Universiti Putra Malaysia (Putra Grant: 9531500).

References

1. D. Barałkiewicz and J. Siepak, “Chromium, Nickel and Cobalt in Environmental Samples and Existing Legal Norms,” Polish J. Environ. Stud. 8(4), 201–208 (1999).

2. F. T. Manheim, “Marine cobalt resources,” Science 232(4750), 600–608 (1986). [CrossRef]  

3. D. P. Vargas, L. Giraldo, and J. C. Moreno-Piraján, “CO2 Adsorption on Activated Carbon Honeycomb-Monoliths: A Comparison of Langmuir and Tóth Models,” Int. J. Mol. Sci. 13(7), 8388–8397 (2012). [CrossRef]  

4. C. Lupi, M. Pasquali, and A. Dell’Era, “Nickel and Cobalt Recycling from Lithium-Ion Batteries by Electrochemical Processes,” Waste Manage. 25(2), 215–220 (2005). [CrossRef]  

5. V. N. Mehta, A. K. Mungara, and S. K. Kailasa, “Dopamine Dithiocarbamate Functionalized Silver Nanoparticles as Colorimetric Sensors for the Detection of Cobalt Ion,” Anal. Methods 5(7), 1818–1822 (2013). [CrossRef]  

6. R. Lauwerys and D. Lison, “Health Risks Associated with Cobalt Exposure An Overview,” Sci. Total Environ. 150(1-3), 1–6 (1994). [CrossRef]  

7. H. I. Choi, J. A. Hong, M. S. Kim, S. E. Lee, S. H. Jung, P. W. Yoon, J. S. Song, and J. J. Kim, “Severe Cardiomyopathy Due to Arthroprosthetic Cobaltism: Report of Two Cases with Different Outcomes,” Cardiovasc. Toxicol. 19(1), 82–89 (2019). [CrossRef]  

8. D. J. Paustenbach, B. E. Tvermoes, K. M. Unice, B. L. Finley, and B. D. Kerger, “A Review of the Health Hazards Posed by Cobalt,” Crit. Rev. Toxicol. 43(4), 316–362 (2013). [CrossRef]  

9. S. Saleviter, Y. W. Fen, N. A. S. Omar, A. A. Zainudin, and N. A. Yusof, “Development of Optical Sensor for Determination of Co(II) Based on Surface Plasmon Resonance Phenomenon,” Sens. Lett. 15(10), 862–867 (2017). [CrossRef]  

10. N. A. Yusof and M. Ahmad, “A Flow Cell Optosensor for Determination of Co(II) Based on Immobilised 2-(4-Pyridylazo)Resorcinol in Chitosan Membrane by Using Stopped Flow, Flow Injection Analysis,” Sens. Actuators, B 86(2-3), 127–133 (2002). [CrossRef]  

11. H. Sharma, A. Singh, N. Kaur, and N. Singh, “ZnO-Based Imine-Linked Coupled Biocompatible Chemosensor for Nanomolar Detection of Co2+,” ACS Sustainable Chem. Eng. 1(12), 1600–1608 (2013). [CrossRef]  

12. M. Zhang, Y. Q. Liu, and B. C. Ye, “Colorimetric Assay for Parallel Detection of Cd2+, Ni2+ and Co2+ Using Peptide-Modified Gold Nanoparticles,” Analyst 137(3), 601–607 (2012). [CrossRef]  

13. H. P. Chiang, Y. C. Wang, P. T. Leung, and W. S. Tse, “A Theoretical Model for the Temperature-dependent Sensitivity of the Optical Sensor Based on Surface Plasmon Resonance,” Opt. Commun. 188(5-6), 283–289 (2001). [CrossRef]  

14. N. A. S. Omar and Y. W. Fen, “Recent Development of SPR Spectroscopy as Potential Method for Diagnosis of Dengue Virus E-Protein,” Sens. Rev. 38(1), 106–116 (2018). [CrossRef]  

15. L. He, Q. Pagneux, I. Larroulet, A. Y. Serrano, A. Pesquera, A. Zurutuza, D. Mandler, R. Boukherroub, and S. Szunerits, “Label-Free Femtomolar Cancer Biomarker Detection in Human Serum Using Graphene-Coated Surface Plasmon Resonance Chips,” Biosens. Bioelectron. 89, 606–611 (2017). [CrossRef]  

16. P. Singh, “SPR Biosensors: Historical Perspectives and Current Challenges,” Sens. Actuators, B 229, 110–130 (2016). [CrossRef]  

17. A. Sionkowska and A. Płanecka, “Surface Properties of Thin Films Based on the Mixtures of Chitosan and Silk Fibroin,” J. Mol. Liq. 186, 157–162 (2013). [CrossRef]  

18. O. Tabasi and C. Falamaki, “Analytical Methods Recent Advancements in the Methodologies Applied for the Sensitivity Enhancement of Surface Plasmon Resonance Sensors,” Sens. Actuators, B 10(32), 3906–3925 (2018).

19. L. Wu, Q. You, Y. Shan, S. Gan, Y. Zhao, and X. Dai, “Few-Layer Ti 3C2Tx MXene : A Promising Surface Plasmon Resonance Biosensing Material to Enhance the Sensitivity,” Sens. Actuators, B 277, 210–215 (2018). [CrossRef]  

20. K. Li, W. Zhou, and S. Zeng, “Optical Micro/Nanofiber-Based Localized Surface Plasmon Resonance Biosensors: Fiber Diameter Dependence,” Sensors 18(10), 3295 (2018). [CrossRef]  

21. N. A. S. Omar, Y. W. Fen, J. Abdullah, M. H. M. Zaid, and M. A. Mahdi, “Structural, Optical and Sensing Properties of CdS-NH2GO Thin Film as a Dengue Virus E-protein Sensing Material,” Optik (Stuttg.) 171, 934–940 (2018). [CrossRef]  

22. Y. W. Fen, W. M. M. Yunus, and N. A. Yusof, “Surface Plasmon Resonance Optical Sensor for Detection of Pb2+ Based on Immobilized P-Tert-Butylcalix[4]Arene-Tetrakis in Chitosan Thin Film as an Active Layer,” Sens. Actuators, B 171-172, 287–293 (2012). [CrossRef]  

23. A. A. Zainudin, Y. W. Fen, N. A. Yusof, S. H. Al-Rekabi, M. A. Mahdi, and N. A. S. Omar, “Incorporation of Surface Plasmon Resonance with Novel Valinomycin Doped Chitosan-Graphene Oxide Thin Film for Sensing Potassium Ion. Spectrochim,” Spectrochim. Acta, Part A 191, 111–115 (2018). [CrossRef]  

24. S. B. D. Borah, T. Bora, S. Baruah, and J. Dutta, “Heavy Metal Ion Sensing in Water Using Surface Plasmon Resonance of Metallic Nanostructures,” Groundw. Sustain. Dev. 1(1-2), 1–11 (2015). [CrossRef]  

25. W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, S. Saleviter, and N. A. Sheh Omar, “Preparation and Characterization of Hexadecyltrimethylammonium Bromide Modified Nanocrystalline Cellulose/Graphene Oxide Composite Thin Film and Its Potential in Sensing Copper Ion Using Surface Plasmon Resonance Technique,” Optik (Stuttg.) 173, 71–77 (2018). [CrossRef]  

26. W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Label-free optical spectroscopy for characterizing binding properties of highly sensitive nanocrystalline cellulose-graphene oxide based nanocomposite towards nickel ion,” Spectrochim. Acta, Part A 212, 25–31 (2019). [CrossRef]  

27. Y. W. Fen, W. M. M. Yunus, and Z. A. Talib, “Analysis of Pb(II) Ion Sensing by Crosslinked Chitosan Thin Film Using Surface Plasmon Resonance Spectroscopy,” Optik (Stuttg.) 124(2), 126–133 (2013). [CrossRef]  

28. Y. W. Fen and W. M. M. Yunus, “Surface Plasmon Resonance Spectroscopy as an Alternative for Sensing Heavy Metal Ions: A Review,” Sens. Rev. 33(4), 305–314 (2013). [CrossRef]  

29. O. Pluchery, R. Vayron, and K. M. Van, “Laboratory Experiments for Exploring the Surface Plasmon Resonance,” Eur. J. Phys. 32(2), 585–599 (2011). [CrossRef]  

30. X. Zhou, K. Chen, L. Li, W. Peng, and Q. Yu, “Angle Modulated Surface Plasmon Resonance Spectrometer for Refractive Index Sensing with Enhanced Detection Resolution,” Opt. Commun. 382, 610–614 (2017). [CrossRef]  

31. A. Paliwal, R. Gaur, A. Sharma, M. Tomar, and V. Gupta, “Sensitive Optical Biosensor Based on Surface Plasmon Resonance Using ZnO/Au Bilayered Structure,” Optik (Stuttg.) 127(19), 7642–7647 (2016). [CrossRef]  

32. A. A. Zainudin, Y. W. Fen, N. A. Yusof, and N. A. S. Omar, “Structural, Optical and Sensing Properties of Ionophore Doped Graphene Based Bionanocomposite Thin Film,” Optik (Stuttg.) 144, 308–315 (2017). [CrossRef]  

33. W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Exploration of Surface Plasmon Resonance for Sensing Copper Ion Based on Nanocrystalline Cellulose-Modified Thin Film,” Opt. Express 26(26), 34880–34893 (2018). [CrossRef]  

34. M. D. A. Roshidi, Y. W. Fen, W. M. E. M. M. Daniyal, N. A. S. Omar, and M. Zulholinda, “Structural and Optical Properties of Chitosan–Poly (amidoamine) Dendrimer Composite Thin Film for Potential Sensing Pb2+ using an Optical Spectroscopy,” Optik (Stuttg.) 185, 351–358 (2019). [CrossRef]  

35. Y. W. Fen, W. M. M. Yunus, and N. A. Yusof, “Optical Properties of Cross-Linked Chitosan Thin Film for Copper Ion Detection Using Surface Plasmon Resonance Technique,” Opt. Appl. 41(4), 999–1013 (2011).

36. B. Yu, J. Xu, J. H. Liu, S. T. Yang, J. Luo, Q. Zhou, J. Wan, R. Liao, H. Wang, and Y. Liu, “Adsorption Behavior of Copper Ions on Graphene Oxide-Chitosan Aerogel,” J. Environ. Chem. Eng. 1(4), 1044–1050 (2013). [CrossRef]  

37. M. N. R. Kumar, “A Review of Chitin and Chitosan Applications. Reactive and Functional Polymers,” React. Funct. Polym. 46(1), 1–27 (2000). [CrossRef]  

38. P. Kanmani, J. Aravind, M. Kamaraj, P. Sureshbabu, and S. Karthikeyan, “Bioresource Technology Environmental Applications of Chitosan and Cellulosic Biopolymers : A Comprehensive Outlook,” Bioresour. Technol. 242, 295–303 (2017). [CrossRef]  

39. X. Luo, J. Zeng, S. Liu, and L. Zhang, “Bioresource Technology an Effective and Recyclable Adsorbent for the Removal of Heavy Metal Ions from Aqueous System : Magnetic Chitosan/Cellulose Microspheres,” Bioresour. Technol. 194, 403–406 (2015). [CrossRef]  

40. N. F. Lokman, A. A. A. Bakar, H. F. S. Abdullah, W. B. W. A. Rahman, N. M. Huang, and M. H. Yaacob, “Highly Sensitive SPR Response of Au/Chitosan/Graphene Oxide Nanostructured Thin Films toward Pb(II) Ions,” Sens. Actuators, B 195, 459–466 (2014). [CrossRef]  

41. X. Huang, Z. Yin, S. Wu, X. Qi, Q. He, Q. Zhang, Q. Yan, F. Boey, and H. Zhang, “Graphene-Based Materials: Synthesis, Characterization, Properties, and Applications,” Small 7(14), 1876–1902 (2011). [CrossRef]  

42. J. Abolhasani, “Fluorescence Quenching of CdS Quantum Dots and Its Application to Determination of Copper and Nickel Contamination in Well and Dam Water,” J. Chem. Heal. Risks 5(2), 145–154 (2015).

43. T. Khantaw, C. Boonmee, T. Tuntulani, and W. Ngeontae, “Selective Turn-on Fluorescence Sensor for Ag+ Using Cysteamine Capped CdS Quantum Dots: Determination of Free Ag+ in Silver Nanoparticles Solution,” Talanta 115, 849–856 (2013). [CrossRef]  

44. S. Liu, W. Na, S. Pang, and X. Su, “Fluorescence Detection of Pb2+based on the DNA Sequence Functionalized CdS Quantum Dots,” Biosens. Bioelectron. 58, 17–21 (2014). [CrossRef]  

45. S. Saleviter, Y. W. Fen, N. A. S. Omar, W. M. E. M. Daniyal, and J. Abdullah, “Structural and Optical Studies of Cadmium Sulfide Quantum Dot-Graphene Oxide-Chitosan Nanocomposite Thin Film as a Novel SPR Spectroscopy Active Layer,” J. Nanomater. 2018, 1–8 (2018). [CrossRef]  

46. M. H. M. Zaid, J. Abdullah, N. A. Yusof, Y. Sulaiman, H. Wasoh, M. F. M. Noh, and R. Issa, “PNA Biosensor Based on Reduced Graphene Oxide/Water Soluble Quantum Dots for the Detection of Mycobacterium Tuberculosis,” Sens. Actuators, B 241, 1024–1034 (2017). [CrossRef]  

47. Y. W. Fen, W. M. M. Yunus, and Z. A. Talib, “Real-Time Monitoring of Lead Ion Interaction on Gold/Chitosan Surface Using Surface Plasmon Resonance Spectroscopy,” Indian J. Phys. 86(7), 619–623 (2012). [CrossRef]  

48. Y. W. Fen and W. M. M. Yunus, “Characterization of the Optical Properties of Heavy Metal Ions Using Surface Plasmon Resonance Technique,” Opt. Photonics J. 01(03), 116–123 (2011). [CrossRef]  

49. Y. W. Fen, W. M. M. Yunus, N. A. Yusof, N. S. Ishak, N. A. S. Omar, and A. A. Zainudin, “Preparation, Characterization and Optical Properties of Ionophore Doped Chitosan Biopolymer Thin Film and Its Potential Application for Sensing Metal Ion,” Optik (Stuttg.) 126(23), 4688–4692 (2015). [CrossRef]  

50. Y. W. Fen, W. M. M. Yunus, Z. A. Talib, and N. A. Yusof, “Development of Surface Plasmon Resonance Sensor for Determining Zinc Ion Using Novel Active Nanolayers as Probe,” Spectrochim. Acta, Part A 134, 48–52 (2015). [CrossRef]  

51. U. Jeong, H. H. Shin, and Y. H. Kim, “Functionalized Magnetic Core-shell Fe@SiO2 Nanoparticles as Recoverable Colorimetric Sensor for Co2+ Ion,” Chem. Eng. J. 281, 428–433 (2015). [CrossRef]  

52. U. B. Patel, V. N. Mehta, A. K. Mungara, and S. K. Kailasa, “4-Aminothiophenol Functionalized Gold Nanoparticles as Colorimetric Sensors for the Detection of Cobalt Using UV–Visible Spectrometry,” Res. Chem. Intermed. 39(2), 771–779 (2013). [CrossRef]  

53. C. H. Zeng, X. T. Meng, S. S. Xu, L. J. Han, S. L. Zhong, and M. Y. Jia, “A Polymorphic Lanthanide Complex as Selective Co2+ Sensor and Luminescent Timer,” Sens. Actuators, B 221, 127–135 (2015). [CrossRef]  

54. D. Kong, F. Y. Yan, J. X. Xu, X. F. Guo, and L. Chen, “Cobalt (II) Ions Detection Using Carbon Dots as an Sensitive and Selective Fluorescent Probe,” RSC Adv. 6(72), 67481–67487 (2016). [CrossRef]  

55. A. A. Alwahib, A. R. Sadrolhosseini, M. N. An’Amt, H. N. Lim, M. H. Yaacob, M. H. A. Bakar, H. N. Ming, and M. A. Mahdi, “Reduced Graphene Oxide/Maghemite Nanocomposite for Detection of Hydrocarbon Vapor Using Surface Plasmon Resonance,” IEEE Photonics J. 8(4), 1–9 (2016). [CrossRef]  

56. N. A. S. Omar, Y. W. Fen, J. Abdullah, C. E. N. C. E. Chik, and M. A. Mahdi, “Development of an Optical Sensor Based on Surface Plasmon Resonance Phenomenon for Diagnosis of Dengue Virus E-Protein,” Water, Air, Soil Pollut. 20, 16–21 (2018). [CrossRef]  

57. N. H. Kamaruddin, A. A. A. Bakar, M. H. Yaacob, M. A. Mahdi, M. S. D. Zan, and S. Shaari, “Enhancement of Chitosan-Graphene Oxide SPR Sensor with a Multi-Metallic Layers of Au-Ag-Au Nanostructure for Lead(II) Ion Detection,” Appl. Surf. Sci. 361, 177–184 (2016). [CrossRef]  

58. N. Kamaruddin, A. A. Bakar, N. Mobarak, M. S. Zan, and N. Arsad, “Binding Affinity of a Highly Sensitive Au/Ag/Au/Chitosan-Graphene Oxide Sensor Based on Direct Detection of Pb2+ and Hg2+ Ions,” Sensors 17(10), 2277 (2017). [CrossRef]  

59. Y. S. Ho, J. F. Porter, and G. McKay, “Equilibrium Isotherm Studies for the Sorption of Divalent Metal Ions onto Peat: Copper, Nickel and Lead Single Component Systems,” Water, Air, Soil Pollut. 141(1/4), 1–33 (2002). [CrossRef]  

60. Y. W. Fen and W. M. M. Yunus, “Utilization of Chitosan-Based Sensor Thin Films for the Detection of Lead Ion by Surface Plasmon Resonance Optical Sensor,” IEEE Sens. J. 13(5), 1413–1418 (2013). [CrossRef]  

61. A. Sharma, R. Jha, and B. Gupta, “Fiber-Optic Sensors Based on Surface Plasmon Resonance: A Comprehensive Review,” IEEE Sens. J. 7(8), 1118–1129 (2007). [CrossRef]  

62. A. R. Sadrolhosseini, M. Naseri, and H. M. Kamari, “Surface Plasmon Resonance Sensor for Detecting of Arsenic in Aqueous Solution Using Polypyrrole-Chitosan-Cobalt Ferrite Nanoparticles Composite Layer,” Opt. Commun. 383, 132–137 (2017). [CrossRef]  

63. S. Yasmeen, M. Kabiraz, B. Saha, M. Qadir, M. Gafur, and S. Masum, “Chromium (VI) Ions Removal from Tannery Effluent Using Chitosan-Microcrystalline Cellulose Composite as Adsorbent,” Int. Res. J. Pure Appl. Chem. 10(4), 1–14 (2016). [CrossRef]  

64. G. P. Jeppu and T. P. A. Clement, “Modified Langmuir-Freundlich Isotherm Model for Simulating PH-Dependent Adsorption Effects,” J. Contam. Hydrol. 129-130, 46–53 (2012). [CrossRef]  

65. M. Asgari, H. Anisi, H. Mohammadi, and S. Sadighi, “Designing a Commercial Scale Pressure Swing Adsorber for Hydrogen Purification,” Pet. Coal. 56(5), 552–561 (2014).

References

  • View by:
  • |
  • |
  • |

  1. D. Barałkiewicz and J. Siepak, “Chromium, Nickel and Cobalt in Environmental Samples and Existing Legal Norms,” Polish J. Environ. Stud. 8(4), 201–208 (1999).
  2. F. T. Manheim, “Marine cobalt resources,” Science 232(4750), 600–608 (1986).
    [Crossref]
  3. D. P. Vargas, L. Giraldo, and J. C. Moreno-Piraján, “CO2 Adsorption on Activated Carbon Honeycomb-Monoliths: A Comparison of Langmuir and Tóth Models,” Int. J. Mol. Sci. 13(7), 8388–8397 (2012).
    [Crossref]
  4. C. Lupi, M. Pasquali, and A. Dell’Era, “Nickel and Cobalt Recycling from Lithium-Ion Batteries by Electrochemical Processes,” Waste Manage. 25(2), 215–220 (2005).
    [Crossref]
  5. V. N. Mehta, A. K. Mungara, and S. K. Kailasa, “Dopamine Dithiocarbamate Functionalized Silver Nanoparticles as Colorimetric Sensors for the Detection of Cobalt Ion,” Anal. Methods 5(7), 1818–1822 (2013).
    [Crossref]
  6. R. Lauwerys and D. Lison, “Health Risks Associated with Cobalt Exposure An Overview,” Sci. Total Environ. 150(1-3), 1–6 (1994).
    [Crossref]
  7. H. I. Choi, J. A. Hong, M. S. Kim, S. E. Lee, S. H. Jung, P. W. Yoon, J. S. Song, and J. J. Kim, “Severe Cardiomyopathy Due to Arthroprosthetic Cobaltism: Report of Two Cases with Different Outcomes,” Cardiovasc. Toxicol. 19(1), 82–89 (2019).
    [Crossref]
  8. D. J. Paustenbach, B. E. Tvermoes, K. M. Unice, B. L. Finley, and B. D. Kerger, “A Review of the Health Hazards Posed by Cobalt,” Crit. Rev. Toxicol. 43(4), 316–362 (2013).
    [Crossref]
  9. S. Saleviter, Y. W. Fen, N. A. S. Omar, A. A. Zainudin, and N. A. Yusof, “Development of Optical Sensor for Determination of Co(II) Based on Surface Plasmon Resonance Phenomenon,” Sens. Lett. 15(10), 862–867 (2017).
    [Crossref]
  10. N. A. Yusof and M. Ahmad, “A Flow Cell Optosensor for Determination of Co(II) Based on Immobilised 2-(4-Pyridylazo)Resorcinol in Chitosan Membrane by Using Stopped Flow, Flow Injection Analysis,” Sens. Actuators, B 86(2-3), 127–133 (2002).
    [Crossref]
  11. H. Sharma, A. Singh, N. Kaur, and N. Singh, “ZnO-Based Imine-Linked Coupled Biocompatible Chemosensor for Nanomolar Detection of Co2+,” ACS Sustainable Chem. Eng. 1(12), 1600–1608 (2013).
    [Crossref]
  12. M. Zhang, Y. Q. Liu, and B. C. Ye, “Colorimetric Assay for Parallel Detection of Cd2+, Ni2+ and Co2+ Using Peptide-Modified Gold Nanoparticles,” Analyst 137(3), 601–607 (2012).
    [Crossref]
  13. H. P. Chiang, Y. C. Wang, P. T. Leung, and W. S. Tse, “A Theoretical Model for the Temperature-dependent Sensitivity of the Optical Sensor Based on Surface Plasmon Resonance,” Opt. Commun. 188(5-6), 283–289 (2001).
    [Crossref]
  14. N. A. S. Omar and Y. W. Fen, “Recent Development of SPR Spectroscopy as Potential Method for Diagnosis of Dengue Virus E-Protein,” Sens. Rev. 38(1), 106–116 (2018).
    [Crossref]
  15. L. He, Q. Pagneux, I. Larroulet, A. Y. Serrano, A. Pesquera, A. Zurutuza, D. Mandler, R. Boukherroub, and S. Szunerits, “Label-Free Femtomolar Cancer Biomarker Detection in Human Serum Using Graphene-Coated Surface Plasmon Resonance Chips,” Biosens. Bioelectron. 89, 606–611 (2017).
    [Crossref]
  16. P. Singh, “SPR Biosensors: Historical Perspectives and Current Challenges,” Sens. Actuators, B 229, 110–130 (2016).
    [Crossref]
  17. A. Sionkowska and A. Płanecka, “Surface Properties of Thin Films Based on the Mixtures of Chitosan and Silk Fibroin,” J. Mol. Liq. 186, 157–162 (2013).
    [Crossref]
  18. O. Tabasi and C. Falamaki, “Analytical Methods Recent Advancements in the Methodologies Applied for the Sensitivity Enhancement of Surface Plasmon Resonance Sensors,” Sens. Actuators, B 10(32), 3906–3925 (2018).
  19. L. Wu, Q. You, Y. Shan, S. Gan, Y. Zhao, and X. Dai, “Few-Layer Ti 3C2Tx MXene : A Promising Surface Plasmon Resonance Biosensing Material to Enhance the Sensitivity,” Sens. Actuators, B 277, 210–215 (2018).
    [Crossref]
  20. K. Li, W. Zhou, and S. Zeng, “Optical Micro/Nanofiber-Based Localized Surface Plasmon Resonance Biosensors: Fiber Diameter Dependence,” Sensors 18(10), 3295 (2018).
    [Crossref]
  21. N. A. S. Omar, Y. W. Fen, J. Abdullah, M. H. M. Zaid, and M. A. Mahdi, “Structural, Optical and Sensing Properties of CdS-NH2GO Thin Film as a Dengue Virus E-protein Sensing Material,” Optik (Stuttg.) 171, 934–940 (2018).
    [Crossref]
  22. Y. W. Fen, W. M. M. Yunus, and N. A. Yusof, “Surface Plasmon Resonance Optical Sensor for Detection of Pb2+ Based on Immobilized P-Tert-Butylcalix[4]Arene-Tetrakis in Chitosan Thin Film as an Active Layer,” Sens. Actuators, B 171-172, 287–293 (2012).
    [Crossref]
  23. A. A. Zainudin, Y. W. Fen, N. A. Yusof, S. H. Al-Rekabi, M. A. Mahdi, and N. A. S. Omar, “Incorporation of Surface Plasmon Resonance with Novel Valinomycin Doped Chitosan-Graphene Oxide Thin Film for Sensing Potassium Ion. Spectrochim,” Spectrochim. Acta, Part A 191, 111–115 (2018).
    [Crossref]
  24. S. B. D. Borah, T. Bora, S. Baruah, and J. Dutta, “Heavy Metal Ion Sensing in Water Using Surface Plasmon Resonance of Metallic Nanostructures,” Groundw. Sustain. Dev. 1(1-2), 1–11 (2015).
    [Crossref]
  25. W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, S. Saleviter, and N. A. Sheh Omar, “Preparation and Characterization of Hexadecyltrimethylammonium Bromide Modified Nanocrystalline Cellulose/Graphene Oxide Composite Thin Film and Its Potential in Sensing Copper Ion Using Surface Plasmon Resonance Technique,” Optik (Stuttg.) 173, 71–77 (2018).
    [Crossref]
  26. W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Label-free optical spectroscopy for characterizing binding properties of highly sensitive nanocrystalline cellulose-graphene oxide based nanocomposite towards nickel ion,” Spectrochim. Acta, Part A 212, 25–31 (2019).
    [Crossref]
  27. Y. W. Fen, W. M. M. Yunus, and Z. A. Talib, “Analysis of Pb(II) Ion Sensing by Crosslinked Chitosan Thin Film Using Surface Plasmon Resonance Spectroscopy,” Optik (Stuttg.) 124(2), 126–133 (2013).
    [Crossref]
  28. Y. W. Fen and W. M. M. Yunus, “Surface Plasmon Resonance Spectroscopy as an Alternative for Sensing Heavy Metal Ions: A Review,” Sens. Rev. 33(4), 305–314 (2013).
    [Crossref]
  29. O. Pluchery, R. Vayron, and K. M. Van, “Laboratory Experiments for Exploring the Surface Plasmon Resonance,” Eur. J. Phys. 32(2), 585–599 (2011).
    [Crossref]
  30. X. Zhou, K. Chen, L. Li, W. Peng, and Q. Yu, “Angle Modulated Surface Plasmon Resonance Spectrometer for Refractive Index Sensing with Enhanced Detection Resolution,” Opt. Commun. 382, 610–614 (2017).
    [Crossref]
  31. A. Paliwal, R. Gaur, A. Sharma, M. Tomar, and V. Gupta, “Sensitive Optical Biosensor Based on Surface Plasmon Resonance Using ZnO/Au Bilayered Structure,” Optik (Stuttg.) 127(19), 7642–7647 (2016).
    [Crossref]
  32. A. A. Zainudin, Y. W. Fen, N. A. Yusof, and N. A. S. Omar, “Structural, Optical and Sensing Properties of Ionophore Doped Graphene Based Bionanocomposite Thin Film,” Optik (Stuttg.) 144, 308–315 (2017).
    [Crossref]
  33. W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Exploration of Surface Plasmon Resonance for Sensing Copper Ion Based on Nanocrystalline Cellulose-Modified Thin Film,” Opt. Express 26(26), 34880–34893 (2018).
    [Crossref]
  34. M. D. A. Roshidi, Y. W. Fen, W. M. E. M. M. Daniyal, N. A. S. Omar, and M. Zulholinda, “Structural and Optical Properties of Chitosan–Poly (amidoamine) Dendrimer Composite Thin Film for Potential Sensing Pb2+ using an Optical Spectroscopy,” Optik (Stuttg.) 185, 351–358 (2019).
    [Crossref]
  35. Y. W. Fen, W. M. M. Yunus, and N. A. Yusof, “Optical Properties of Cross-Linked Chitosan Thin Film for Copper Ion Detection Using Surface Plasmon Resonance Technique,” Opt. Appl. 41(4), 999–1013 (2011).
  36. B. Yu, J. Xu, J. H. Liu, S. T. Yang, J. Luo, Q. Zhou, J. Wan, R. Liao, H. Wang, and Y. Liu, “Adsorption Behavior of Copper Ions on Graphene Oxide-Chitosan Aerogel,” J. Environ. Chem. Eng. 1(4), 1044–1050 (2013).
    [Crossref]
  37. M. N. R. Kumar, “A Review of Chitin and Chitosan Applications. Reactive and Functional Polymers,” React. Funct. Polym. 46(1), 1–27 (2000).
    [Crossref]
  38. P. Kanmani, J. Aravind, M. Kamaraj, P. Sureshbabu, and S. Karthikeyan, “Bioresource Technology Environmental Applications of Chitosan and Cellulosic Biopolymers : A Comprehensive Outlook,” Bioresour. Technol. 242, 295–303 (2017).
    [Crossref]
  39. X. Luo, J. Zeng, S. Liu, and L. Zhang, “Bioresource Technology an Effective and Recyclable Adsorbent for the Removal of Heavy Metal Ions from Aqueous System : Magnetic Chitosan/Cellulose Microspheres,” Bioresour. Technol. 194, 403–406 (2015).
    [Crossref]
  40. N. F. Lokman, A. A. A. Bakar, H. F. S. Abdullah, W. B. W. A. Rahman, N. M. Huang, and M. H. Yaacob, “Highly Sensitive SPR Response of Au/Chitosan/Graphene Oxide Nanostructured Thin Films toward Pb(II) Ions,” Sens. Actuators, B 195, 459–466 (2014).
    [Crossref]
  41. X. Huang, Z. Yin, S. Wu, X. Qi, Q. He, Q. Zhang, Q. Yan, F. Boey, and H. Zhang, “Graphene-Based Materials: Synthesis, Characterization, Properties, and Applications,” Small 7(14), 1876–1902 (2011).
    [Crossref]
  42. J. Abolhasani, “Fluorescence Quenching of CdS Quantum Dots and Its Application to Determination of Copper and Nickel Contamination in Well and Dam Water,” J. Chem. Heal. Risks 5(2), 145–154 (2015).
  43. T. Khantaw, C. Boonmee, T. Tuntulani, and W. Ngeontae, “Selective Turn-on Fluorescence Sensor for Ag+ Using Cysteamine Capped CdS Quantum Dots: Determination of Free Ag+ in Silver Nanoparticles Solution,” Talanta 115, 849–856 (2013).
    [Crossref]
  44. S. Liu, W. Na, S. Pang, and X. Su, “Fluorescence Detection of Pb2+based on the DNA Sequence Functionalized CdS Quantum Dots,” Biosens. Bioelectron. 58, 17–21 (2014).
    [Crossref]
  45. S. Saleviter, Y. W. Fen, N. A. S. Omar, W. M. E. M. Daniyal, and J. Abdullah, “Structural and Optical Studies of Cadmium Sulfide Quantum Dot-Graphene Oxide-Chitosan Nanocomposite Thin Film as a Novel SPR Spectroscopy Active Layer,” J. Nanomater. 2018, 1–8 (2018).
    [Crossref]
  46. M. H. M. Zaid, J. Abdullah, N. A. Yusof, Y. Sulaiman, H. Wasoh, M. F. M. Noh, and R. Issa, “PNA Biosensor Based on Reduced Graphene Oxide/Water Soluble Quantum Dots for the Detection of Mycobacterium Tuberculosis,” Sens. Actuators, B 241, 1024–1034 (2017).
    [Crossref]
  47. Y. W. Fen, W. M. M. Yunus, and Z. A. Talib, “Real-Time Monitoring of Lead Ion Interaction on Gold/Chitosan Surface Using Surface Plasmon Resonance Spectroscopy,” Indian J. Phys. 86(7), 619–623 (2012).
    [Crossref]
  48. Y. W. Fen and W. M. M. Yunus, “Characterization of the Optical Properties of Heavy Metal Ions Using Surface Plasmon Resonance Technique,” Opt. Photonics J. 01(03), 116–123 (2011).
    [Crossref]
  49. Y. W. Fen, W. M. M. Yunus, N. A. Yusof, N. S. Ishak, N. A. S. Omar, and A. A. Zainudin, “Preparation, Characterization and Optical Properties of Ionophore Doped Chitosan Biopolymer Thin Film and Its Potential Application for Sensing Metal Ion,” Optik (Stuttg.) 126(23), 4688–4692 (2015).
    [Crossref]
  50. Y. W. Fen, W. M. M. Yunus, Z. A. Talib, and N. A. Yusof, “Development of Surface Plasmon Resonance Sensor for Determining Zinc Ion Using Novel Active Nanolayers as Probe,” Spectrochim. Acta, Part A 134, 48–52 (2015).
    [Crossref]
  51. U. Jeong, H. H. Shin, and Y. H. Kim, “Functionalized Magnetic Core-shell Fe@SiO2 Nanoparticles as Recoverable Colorimetric Sensor for Co2+ Ion,” Chem. Eng. J. 281, 428–433 (2015).
    [Crossref]
  52. U. B. Patel, V. N. Mehta, A. K. Mungara, and S. K. Kailasa, “4-Aminothiophenol Functionalized Gold Nanoparticles as Colorimetric Sensors for the Detection of Cobalt Using UV–Visible Spectrometry,” Res. Chem. Intermed. 39(2), 771–779 (2013).
    [Crossref]
  53. C. H. Zeng, X. T. Meng, S. S. Xu, L. J. Han, S. L. Zhong, and M. Y. Jia, “A Polymorphic Lanthanide Complex as Selective Co2+ Sensor and Luminescent Timer,” Sens. Actuators, B 221, 127–135 (2015).
    [Crossref]
  54. D. Kong, F. Y. Yan, J. X. Xu, X. F. Guo, and L. Chen, “Cobalt (II) Ions Detection Using Carbon Dots as an Sensitive and Selective Fluorescent Probe,” RSC Adv. 6(72), 67481–67487 (2016).
    [Crossref]
  55. A. A. Alwahib, A. R. Sadrolhosseini, M. N. An’Amt, H. N. Lim, M. H. Yaacob, M. H. A. Bakar, H. N. Ming, and M. A. Mahdi, “Reduced Graphene Oxide/Maghemite Nanocomposite for Detection of Hydrocarbon Vapor Using Surface Plasmon Resonance,” IEEE Photonics J. 8(4), 1–9 (2016).
    [Crossref]
  56. N. A. S. Omar, Y. W. Fen, J. Abdullah, C. E. N. C. E. Chik, and M. A. Mahdi, “Development of an Optical Sensor Based on Surface Plasmon Resonance Phenomenon for Diagnosis of Dengue Virus E-Protein,” Water, Air, Soil Pollut. 20, 16–21 (2018).
    [Crossref]
  57. N. H. Kamaruddin, A. A. A. Bakar, M. H. Yaacob, M. A. Mahdi, M. S. D. Zan, and S. Shaari, “Enhancement of Chitosan-Graphene Oxide SPR Sensor with a Multi-Metallic Layers of Au-Ag-Au Nanostructure for Lead(II) Ion Detection,” Appl. Surf. Sci. 361, 177–184 (2016).
    [Crossref]
  58. N. Kamaruddin, A. A. Bakar, N. Mobarak, M. S. Zan, and N. Arsad, “Binding Affinity of a Highly Sensitive Au/Ag/Au/Chitosan-Graphene Oxide Sensor Based on Direct Detection of Pb2+ and Hg2+ Ions,” Sensors 17(10), 2277 (2017).
    [Crossref]
  59. Y. S. Ho, J. F. Porter, and G. McKay, “Equilibrium Isotherm Studies for the Sorption of Divalent Metal Ions onto Peat: Copper, Nickel and Lead Single Component Systems,” Water, Air, Soil Pollut. 141(1/4), 1–33 (2002).
    [Crossref]
  60. Y. W. Fen and W. M. M. Yunus, “Utilization of Chitosan-Based Sensor Thin Films for the Detection of Lead Ion by Surface Plasmon Resonance Optical Sensor,” IEEE Sens. J. 13(5), 1413–1418 (2013).
    [Crossref]
  61. A. Sharma, R. Jha, and B. Gupta, “Fiber-Optic Sensors Based on Surface Plasmon Resonance: A Comprehensive Review,” IEEE Sens. J. 7(8), 1118–1129 (2007).
    [Crossref]
  62. A. R. Sadrolhosseini, M. Naseri, and H. M. Kamari, “Surface Plasmon Resonance Sensor for Detecting of Arsenic in Aqueous Solution Using Polypyrrole-Chitosan-Cobalt Ferrite Nanoparticles Composite Layer,” Opt. Commun. 383, 132–137 (2017).
    [Crossref]
  63. S. Yasmeen, M. Kabiraz, B. Saha, M. Qadir, M. Gafur, and S. Masum, “Chromium (VI) Ions Removal from Tannery Effluent Using Chitosan-Microcrystalline Cellulose Composite as Adsorbent,” Int. Res. J. Pure Appl. Chem. 10(4), 1–14 (2016).
    [Crossref]
  64. G. P. Jeppu and T. P. A. Clement, “Modified Langmuir-Freundlich Isotherm Model for Simulating PH-Dependent Adsorption Effects,” J. Contam. Hydrol. 129-130, 46–53 (2012).
    [Crossref]
  65. M. Asgari, H. Anisi, H. Mohammadi, and S. Sadighi, “Designing a Commercial Scale Pressure Swing Adsorber for Hydrogen Purification,” Pet. Coal. 56(5), 552–561 (2014).

2019 (3)

H. I. Choi, J. A. Hong, M. S. Kim, S. E. Lee, S. H. Jung, P. W. Yoon, J. S. Song, and J. J. Kim, “Severe Cardiomyopathy Due to Arthroprosthetic Cobaltism: Report of Two Cases with Different Outcomes,” Cardiovasc. Toxicol. 19(1), 82–89 (2019).
[Crossref]

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Label-free optical spectroscopy for characterizing binding properties of highly sensitive nanocrystalline cellulose-graphene oxide based nanocomposite towards nickel ion,” Spectrochim. Acta, Part A 212, 25–31 (2019).
[Crossref]

M. D. A. Roshidi, Y. W. Fen, W. M. E. M. M. Daniyal, N. A. S. Omar, and M. Zulholinda, “Structural and Optical Properties of Chitosan–Poly (amidoamine) Dendrimer Composite Thin Film for Potential Sensing Pb2+ using an Optical Spectroscopy,” Optik (Stuttg.) 185, 351–358 (2019).
[Crossref]

2018 (10)

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, S. Saleviter, and N. A. Sheh Omar, “Preparation and Characterization of Hexadecyltrimethylammonium Bromide Modified Nanocrystalline Cellulose/Graphene Oxide Composite Thin Film and Its Potential in Sensing Copper Ion Using Surface Plasmon Resonance Technique,” Optik (Stuttg.) 173, 71–77 (2018).
[Crossref]

A. A. Zainudin, Y. W. Fen, N. A. Yusof, S. H. Al-Rekabi, M. A. Mahdi, and N. A. S. Omar, “Incorporation of Surface Plasmon Resonance with Novel Valinomycin Doped Chitosan-Graphene Oxide Thin Film for Sensing Potassium Ion. Spectrochim,” Spectrochim. Acta, Part A 191, 111–115 (2018).
[Crossref]

O. Tabasi and C. Falamaki, “Analytical Methods Recent Advancements in the Methodologies Applied for the Sensitivity Enhancement of Surface Plasmon Resonance Sensors,” Sens. Actuators, B 10(32), 3906–3925 (2018).

L. Wu, Q. You, Y. Shan, S. Gan, Y. Zhao, and X. Dai, “Few-Layer Ti 3C2Tx MXene : A Promising Surface Plasmon Resonance Biosensing Material to Enhance the Sensitivity,” Sens. Actuators, B 277, 210–215 (2018).
[Crossref]

K. Li, W. Zhou, and S. Zeng, “Optical Micro/Nanofiber-Based Localized Surface Plasmon Resonance Biosensors: Fiber Diameter Dependence,” Sensors 18(10), 3295 (2018).
[Crossref]

N. A. S. Omar, Y. W. Fen, J. Abdullah, M. H. M. Zaid, and M. A. Mahdi, “Structural, Optical and Sensing Properties of CdS-NH2GO Thin Film as a Dengue Virus E-protein Sensing Material,” Optik (Stuttg.) 171, 934–940 (2018).
[Crossref]

N. A. S. Omar and Y. W. Fen, “Recent Development of SPR Spectroscopy as Potential Method for Diagnosis of Dengue Virus E-Protein,” Sens. Rev. 38(1), 106–116 (2018).
[Crossref]

S. Saleviter, Y. W. Fen, N. A. S. Omar, W. M. E. M. Daniyal, and J. Abdullah, “Structural and Optical Studies of Cadmium Sulfide Quantum Dot-Graphene Oxide-Chitosan Nanocomposite Thin Film as a Novel SPR Spectroscopy Active Layer,” J. Nanomater. 2018, 1–8 (2018).
[Crossref]

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Exploration of Surface Plasmon Resonance for Sensing Copper Ion Based on Nanocrystalline Cellulose-Modified Thin Film,” Opt. Express 26(26), 34880–34893 (2018).
[Crossref]

N. A. S. Omar, Y. W. Fen, J. Abdullah, C. E. N. C. E. Chik, and M. A. Mahdi, “Development of an Optical Sensor Based on Surface Plasmon Resonance Phenomenon for Diagnosis of Dengue Virus E-Protein,” Water, Air, Soil Pollut. 20, 16–21 (2018).
[Crossref]

2017 (8)

N. Kamaruddin, A. A. Bakar, N. Mobarak, M. S. Zan, and N. Arsad, “Binding Affinity of a Highly Sensitive Au/Ag/Au/Chitosan-Graphene Oxide Sensor Based on Direct Detection of Pb2+ and Hg2+ Ions,” Sensors 17(10), 2277 (2017).
[Crossref]

A. R. Sadrolhosseini, M. Naseri, and H. M. Kamari, “Surface Plasmon Resonance Sensor for Detecting of Arsenic in Aqueous Solution Using Polypyrrole-Chitosan-Cobalt Ferrite Nanoparticles Composite Layer,” Opt. Commun. 383, 132–137 (2017).
[Crossref]

M. H. M. Zaid, J. Abdullah, N. A. Yusof, Y. Sulaiman, H. Wasoh, M. F. M. Noh, and R. Issa, “PNA Biosensor Based on Reduced Graphene Oxide/Water Soluble Quantum Dots for the Detection of Mycobacterium Tuberculosis,” Sens. Actuators, B 241, 1024–1034 (2017).
[Crossref]

P. Kanmani, J. Aravind, M. Kamaraj, P. Sureshbabu, and S. Karthikeyan, “Bioresource Technology Environmental Applications of Chitosan and Cellulosic Biopolymers : A Comprehensive Outlook,” Bioresour. Technol. 242, 295–303 (2017).
[Crossref]

L. He, Q. Pagneux, I. Larroulet, A. Y. Serrano, A. Pesquera, A. Zurutuza, D. Mandler, R. Boukherroub, and S. Szunerits, “Label-Free Femtomolar Cancer Biomarker Detection in Human Serum Using Graphene-Coated Surface Plasmon Resonance Chips,” Biosens. Bioelectron. 89, 606–611 (2017).
[Crossref]

S. Saleviter, Y. W. Fen, N. A. S. Omar, A. A. Zainudin, and N. A. Yusof, “Development of Optical Sensor for Determination of Co(II) Based on Surface Plasmon Resonance Phenomenon,” Sens. Lett. 15(10), 862–867 (2017).
[Crossref]

X. Zhou, K. Chen, L. Li, W. Peng, and Q. Yu, “Angle Modulated Surface Plasmon Resonance Spectrometer for Refractive Index Sensing with Enhanced Detection Resolution,” Opt. Commun. 382, 610–614 (2017).
[Crossref]

A. A. Zainudin, Y. W. Fen, N. A. Yusof, and N. A. S. Omar, “Structural, Optical and Sensing Properties of Ionophore Doped Graphene Based Bionanocomposite Thin Film,” Optik (Stuttg.) 144, 308–315 (2017).
[Crossref]

2016 (6)

A. Paliwal, R. Gaur, A. Sharma, M. Tomar, and V. Gupta, “Sensitive Optical Biosensor Based on Surface Plasmon Resonance Using ZnO/Au Bilayered Structure,” Optik (Stuttg.) 127(19), 7642–7647 (2016).
[Crossref]

P. Singh, “SPR Biosensors: Historical Perspectives and Current Challenges,” Sens. Actuators, B 229, 110–130 (2016).
[Crossref]

S. Yasmeen, M. Kabiraz, B. Saha, M. Qadir, M. Gafur, and S. Masum, “Chromium (VI) Ions Removal from Tannery Effluent Using Chitosan-Microcrystalline Cellulose Composite as Adsorbent,” Int. Res. J. Pure Appl. Chem. 10(4), 1–14 (2016).
[Crossref]

N. H. Kamaruddin, A. A. A. Bakar, M. H. Yaacob, M. A. Mahdi, M. S. D. Zan, and S. Shaari, “Enhancement of Chitosan-Graphene Oxide SPR Sensor with a Multi-Metallic Layers of Au-Ag-Au Nanostructure for Lead(II) Ion Detection,” Appl. Surf. Sci. 361, 177–184 (2016).
[Crossref]

D. Kong, F. Y. Yan, J. X. Xu, X. F. Guo, and L. Chen, “Cobalt (II) Ions Detection Using Carbon Dots as an Sensitive and Selective Fluorescent Probe,” RSC Adv. 6(72), 67481–67487 (2016).
[Crossref]

A. A. Alwahib, A. R. Sadrolhosseini, M. N. An’Amt, H. N. Lim, M. H. Yaacob, M. H. A. Bakar, H. N. Ming, and M. A. Mahdi, “Reduced Graphene Oxide/Maghemite Nanocomposite for Detection of Hydrocarbon Vapor Using Surface Plasmon Resonance,” IEEE Photonics J. 8(4), 1–9 (2016).
[Crossref]

2015 (7)

C. H. Zeng, X. T. Meng, S. S. Xu, L. J. Han, S. L. Zhong, and M. Y. Jia, “A Polymorphic Lanthanide Complex as Selective Co2+ Sensor and Luminescent Timer,” Sens. Actuators, B 221, 127–135 (2015).
[Crossref]

X. Luo, J. Zeng, S. Liu, and L. Zhang, “Bioresource Technology an Effective and Recyclable Adsorbent for the Removal of Heavy Metal Ions from Aqueous System : Magnetic Chitosan/Cellulose Microspheres,” Bioresour. Technol. 194, 403–406 (2015).
[Crossref]

J. Abolhasani, “Fluorescence Quenching of CdS Quantum Dots and Its Application to Determination of Copper and Nickel Contamination in Well and Dam Water,” J. Chem. Heal. Risks 5(2), 145–154 (2015).

Y. W. Fen, W. M. M. Yunus, N. A. Yusof, N. S. Ishak, N. A. S. Omar, and A. A. Zainudin, “Preparation, Characterization and Optical Properties of Ionophore Doped Chitosan Biopolymer Thin Film and Its Potential Application for Sensing Metal Ion,” Optik (Stuttg.) 126(23), 4688–4692 (2015).
[Crossref]

Y. W. Fen, W. M. M. Yunus, Z. A. Talib, and N. A. Yusof, “Development of Surface Plasmon Resonance Sensor for Determining Zinc Ion Using Novel Active Nanolayers as Probe,” Spectrochim. Acta, Part A 134, 48–52 (2015).
[Crossref]

U. Jeong, H. H. Shin, and Y. H. Kim, “Functionalized Magnetic Core-shell Fe@SiO2 Nanoparticles as Recoverable Colorimetric Sensor for Co2+ Ion,” Chem. Eng. J. 281, 428–433 (2015).
[Crossref]

S. B. D. Borah, T. Bora, S. Baruah, and J. Dutta, “Heavy Metal Ion Sensing in Water Using Surface Plasmon Resonance of Metallic Nanostructures,” Groundw. Sustain. Dev. 1(1-2), 1–11 (2015).
[Crossref]

2014 (3)

N. F. Lokman, A. A. A. Bakar, H. F. S. Abdullah, W. B. W. A. Rahman, N. M. Huang, and M. H. Yaacob, “Highly Sensitive SPR Response of Au/Chitosan/Graphene Oxide Nanostructured Thin Films toward Pb(II) Ions,” Sens. Actuators, B 195, 459–466 (2014).
[Crossref]

M. Asgari, H. Anisi, H. Mohammadi, and S. Sadighi, “Designing a Commercial Scale Pressure Swing Adsorber for Hydrogen Purification,” Pet. Coal. 56(5), 552–561 (2014).

S. Liu, W. Na, S. Pang, and X. Su, “Fluorescence Detection of Pb2+based on the DNA Sequence Functionalized CdS Quantum Dots,” Biosens. Bioelectron. 58, 17–21 (2014).
[Crossref]

2013 (10)

Y. W. Fen and W. M. M. Yunus, “Utilization of Chitosan-Based Sensor Thin Films for the Detection of Lead Ion by Surface Plasmon Resonance Optical Sensor,” IEEE Sens. J. 13(5), 1413–1418 (2013).
[Crossref]

T. Khantaw, C. Boonmee, T. Tuntulani, and W. Ngeontae, “Selective Turn-on Fluorescence Sensor for Ag+ Using Cysteamine Capped CdS Quantum Dots: Determination of Free Ag+ in Silver Nanoparticles Solution,” Talanta 115, 849–856 (2013).
[Crossref]

B. Yu, J. Xu, J. H. Liu, S. T. Yang, J. Luo, Q. Zhou, J. Wan, R. Liao, H. Wang, and Y. Liu, “Adsorption Behavior of Copper Ions on Graphene Oxide-Chitosan Aerogel,” J. Environ. Chem. Eng. 1(4), 1044–1050 (2013).
[Crossref]

U. B. Patel, V. N. Mehta, A. K. Mungara, and S. K. Kailasa, “4-Aminothiophenol Functionalized Gold Nanoparticles as Colorimetric Sensors for the Detection of Cobalt Using UV–Visible Spectrometry,” Res. Chem. Intermed. 39(2), 771–779 (2013).
[Crossref]

Y. W. Fen, W. M. M. Yunus, and Z. A. Talib, “Analysis of Pb(II) Ion Sensing by Crosslinked Chitosan Thin Film Using Surface Plasmon Resonance Spectroscopy,” Optik (Stuttg.) 124(2), 126–133 (2013).
[Crossref]

Y. W. Fen and W. M. M. Yunus, “Surface Plasmon Resonance Spectroscopy as an Alternative for Sensing Heavy Metal Ions: A Review,” Sens. Rev. 33(4), 305–314 (2013).
[Crossref]

A. Sionkowska and A. Płanecka, “Surface Properties of Thin Films Based on the Mixtures of Chitosan and Silk Fibroin,” J. Mol. Liq. 186, 157–162 (2013).
[Crossref]

H. Sharma, A. Singh, N. Kaur, and N. Singh, “ZnO-Based Imine-Linked Coupled Biocompatible Chemosensor for Nanomolar Detection of Co2+,” ACS Sustainable Chem. Eng. 1(12), 1600–1608 (2013).
[Crossref]

D. J. Paustenbach, B. E. Tvermoes, K. M. Unice, B. L. Finley, and B. D. Kerger, “A Review of the Health Hazards Posed by Cobalt,” Crit. Rev. Toxicol. 43(4), 316–362 (2013).
[Crossref]

V. N. Mehta, A. K. Mungara, and S. K. Kailasa, “Dopamine Dithiocarbamate Functionalized Silver Nanoparticles as Colorimetric Sensors for the Detection of Cobalt Ion,” Anal. Methods 5(7), 1818–1822 (2013).
[Crossref]

2012 (5)

D. P. Vargas, L. Giraldo, and J. C. Moreno-Piraján, “CO2 Adsorption on Activated Carbon Honeycomb-Monoliths: A Comparison of Langmuir and Tóth Models,” Int. J. Mol. Sci. 13(7), 8388–8397 (2012).
[Crossref]

M. Zhang, Y. Q. Liu, and B. C. Ye, “Colorimetric Assay for Parallel Detection of Cd2+, Ni2+ and Co2+ Using Peptide-Modified Gold Nanoparticles,” Analyst 137(3), 601–607 (2012).
[Crossref]

Y. W. Fen, W. M. M. Yunus, and N. A. Yusof, “Surface Plasmon Resonance Optical Sensor for Detection of Pb2+ Based on Immobilized P-Tert-Butylcalix[4]Arene-Tetrakis in Chitosan Thin Film as an Active Layer,” Sens. Actuators, B 171-172, 287–293 (2012).
[Crossref]

Y. W. Fen, W. M. M. Yunus, and Z. A. Talib, “Real-Time Monitoring of Lead Ion Interaction on Gold/Chitosan Surface Using Surface Plasmon Resonance Spectroscopy,” Indian J. Phys. 86(7), 619–623 (2012).
[Crossref]

G. P. Jeppu and T. P. A. Clement, “Modified Langmuir-Freundlich Isotherm Model for Simulating PH-Dependent Adsorption Effects,” J. Contam. Hydrol. 129-130, 46–53 (2012).
[Crossref]

2011 (4)

Y. W. Fen and W. M. M. Yunus, “Characterization of the Optical Properties of Heavy Metal Ions Using Surface Plasmon Resonance Technique,” Opt. Photonics J. 01(03), 116–123 (2011).
[Crossref]

X. Huang, Z. Yin, S. Wu, X. Qi, Q. He, Q. Zhang, Q. Yan, F. Boey, and H. Zhang, “Graphene-Based Materials: Synthesis, Characterization, Properties, and Applications,” Small 7(14), 1876–1902 (2011).
[Crossref]

O. Pluchery, R. Vayron, and K. M. Van, “Laboratory Experiments for Exploring the Surface Plasmon Resonance,” Eur. J. Phys. 32(2), 585–599 (2011).
[Crossref]

Y. W. Fen, W. M. M. Yunus, and N. A. Yusof, “Optical Properties of Cross-Linked Chitosan Thin Film for Copper Ion Detection Using Surface Plasmon Resonance Technique,” Opt. Appl. 41(4), 999–1013 (2011).

2007 (1)

A. Sharma, R. Jha, and B. Gupta, “Fiber-Optic Sensors Based on Surface Plasmon Resonance: A Comprehensive Review,” IEEE Sens. J. 7(8), 1118–1129 (2007).
[Crossref]

2005 (1)

C. Lupi, M. Pasquali, and A. Dell’Era, “Nickel and Cobalt Recycling from Lithium-Ion Batteries by Electrochemical Processes,” Waste Manage. 25(2), 215–220 (2005).
[Crossref]

2002 (2)

N. A. Yusof and M. Ahmad, “A Flow Cell Optosensor for Determination of Co(II) Based on Immobilised 2-(4-Pyridylazo)Resorcinol in Chitosan Membrane by Using Stopped Flow, Flow Injection Analysis,” Sens. Actuators, B 86(2-3), 127–133 (2002).
[Crossref]

Y. S. Ho, J. F. Porter, and G. McKay, “Equilibrium Isotherm Studies for the Sorption of Divalent Metal Ions onto Peat: Copper, Nickel and Lead Single Component Systems,” Water, Air, Soil Pollut. 141(1/4), 1–33 (2002).
[Crossref]

2001 (1)

H. P. Chiang, Y. C. Wang, P. T. Leung, and W. S. Tse, “A Theoretical Model for the Temperature-dependent Sensitivity of the Optical Sensor Based on Surface Plasmon Resonance,” Opt. Commun. 188(5-6), 283–289 (2001).
[Crossref]

2000 (1)

M. N. R. Kumar, “A Review of Chitin and Chitosan Applications. Reactive and Functional Polymers,” React. Funct. Polym. 46(1), 1–27 (2000).
[Crossref]

1999 (1)

D. Barałkiewicz and J. Siepak, “Chromium, Nickel and Cobalt in Environmental Samples and Existing Legal Norms,” Polish J. Environ. Stud. 8(4), 201–208 (1999).

1994 (1)

R. Lauwerys and D. Lison, “Health Risks Associated with Cobalt Exposure An Overview,” Sci. Total Environ. 150(1-3), 1–6 (1994).
[Crossref]

1986 (1)

F. T. Manheim, “Marine cobalt resources,” Science 232(4750), 600–608 (1986).
[Crossref]

Abdullah, H. F. S.

N. F. Lokman, A. A. A. Bakar, H. F. S. Abdullah, W. B. W. A. Rahman, N. M. Huang, and M. H. Yaacob, “Highly Sensitive SPR Response of Au/Chitosan/Graphene Oxide Nanostructured Thin Films toward Pb(II) Ions,” Sens. Actuators, B 195, 459–466 (2014).
[Crossref]

Abdullah, J.

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Label-free optical spectroscopy for characterizing binding properties of highly sensitive nanocrystalline cellulose-graphene oxide based nanocomposite towards nickel ion,” Spectrochim. Acta, Part A 212, 25–31 (2019).
[Crossref]

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, S. Saleviter, and N. A. Sheh Omar, “Preparation and Characterization of Hexadecyltrimethylammonium Bromide Modified Nanocrystalline Cellulose/Graphene Oxide Composite Thin Film and Its Potential in Sensing Copper Ion Using Surface Plasmon Resonance Technique,” Optik (Stuttg.) 173, 71–77 (2018).
[Crossref]

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Exploration of Surface Plasmon Resonance for Sensing Copper Ion Based on Nanocrystalline Cellulose-Modified Thin Film,” Opt. Express 26(26), 34880–34893 (2018).
[Crossref]

N. A. S. Omar, Y. W. Fen, J. Abdullah, M. H. M. Zaid, and M. A. Mahdi, “Structural, Optical and Sensing Properties of CdS-NH2GO Thin Film as a Dengue Virus E-protein Sensing Material,” Optik (Stuttg.) 171, 934–940 (2018).
[Crossref]

S. Saleviter, Y. W. Fen, N. A. S. Omar, W. M. E. M. Daniyal, and J. Abdullah, “Structural and Optical Studies of Cadmium Sulfide Quantum Dot-Graphene Oxide-Chitosan Nanocomposite Thin Film as a Novel SPR Spectroscopy Active Layer,” J. Nanomater. 2018, 1–8 (2018).
[Crossref]

N. A. S. Omar, Y. W. Fen, J. Abdullah, C. E. N. C. E. Chik, and M. A. Mahdi, “Development of an Optical Sensor Based on Surface Plasmon Resonance Phenomenon for Diagnosis of Dengue Virus E-Protein,” Water, Air, Soil Pollut. 20, 16–21 (2018).
[Crossref]

M. H. M. Zaid, J. Abdullah, N. A. Yusof, Y. Sulaiman, H. Wasoh, M. F. M. Noh, and R. Issa, “PNA Biosensor Based on Reduced Graphene Oxide/Water Soluble Quantum Dots for the Detection of Mycobacterium Tuberculosis,” Sens. Actuators, B 241, 1024–1034 (2017).
[Crossref]

Abolhasani, J.

J. Abolhasani, “Fluorescence Quenching of CdS Quantum Dots and Its Application to Determination of Copper and Nickel Contamination in Well and Dam Water,” J. Chem. Heal. Risks 5(2), 145–154 (2015).

Ahmad, M.

N. A. Yusof and M. Ahmad, “A Flow Cell Optosensor for Determination of Co(II) Based on Immobilised 2-(4-Pyridylazo)Resorcinol in Chitosan Membrane by Using Stopped Flow, Flow Injection Analysis,” Sens. Actuators, B 86(2-3), 127–133 (2002).
[Crossref]

Al-Rekabi, S. H.

A. A. Zainudin, Y. W. Fen, N. A. Yusof, S. H. Al-Rekabi, M. A. Mahdi, and N. A. S. Omar, “Incorporation of Surface Plasmon Resonance with Novel Valinomycin Doped Chitosan-Graphene Oxide Thin Film for Sensing Potassium Ion. Spectrochim,” Spectrochim. Acta, Part A 191, 111–115 (2018).
[Crossref]

Alwahib, A. A.

A. A. Alwahib, A. R. Sadrolhosseini, M. N. An’Amt, H. N. Lim, M. H. Yaacob, M. H. A. Bakar, H. N. Ming, and M. A. Mahdi, “Reduced Graphene Oxide/Maghemite Nanocomposite for Detection of Hydrocarbon Vapor Using Surface Plasmon Resonance,” IEEE Photonics J. 8(4), 1–9 (2016).
[Crossref]

An’Amt, M. N.

A. A. Alwahib, A. R. Sadrolhosseini, M. N. An’Amt, H. N. Lim, M. H. Yaacob, M. H. A. Bakar, H. N. Ming, and M. A. Mahdi, “Reduced Graphene Oxide/Maghemite Nanocomposite for Detection of Hydrocarbon Vapor Using Surface Plasmon Resonance,” IEEE Photonics J. 8(4), 1–9 (2016).
[Crossref]

Anisi, H.

M. Asgari, H. Anisi, H. Mohammadi, and S. Sadighi, “Designing a Commercial Scale Pressure Swing Adsorber for Hydrogen Purification,” Pet. Coal. 56(5), 552–561 (2014).

Aravind, J.

P. Kanmani, J. Aravind, M. Kamaraj, P. Sureshbabu, and S. Karthikeyan, “Bioresource Technology Environmental Applications of Chitosan and Cellulosic Biopolymers : A Comprehensive Outlook,” Bioresour. Technol. 242, 295–303 (2017).
[Crossref]

Arsad, N.

N. Kamaruddin, A. A. Bakar, N. Mobarak, M. S. Zan, and N. Arsad, “Binding Affinity of a Highly Sensitive Au/Ag/Au/Chitosan-Graphene Oxide Sensor Based on Direct Detection of Pb2+ and Hg2+ Ions,” Sensors 17(10), 2277 (2017).
[Crossref]

Asgari, M.

M. Asgari, H. Anisi, H. Mohammadi, and S. Sadighi, “Designing a Commercial Scale Pressure Swing Adsorber for Hydrogen Purification,” Pet. Coal. 56(5), 552–561 (2014).

Bakar, A. A.

N. Kamaruddin, A. A. Bakar, N. Mobarak, M. S. Zan, and N. Arsad, “Binding Affinity of a Highly Sensitive Au/Ag/Au/Chitosan-Graphene Oxide Sensor Based on Direct Detection of Pb2+ and Hg2+ Ions,” Sensors 17(10), 2277 (2017).
[Crossref]

Bakar, A. A. A.

N. H. Kamaruddin, A. A. A. Bakar, M. H. Yaacob, M. A. Mahdi, M. S. D. Zan, and S. Shaari, “Enhancement of Chitosan-Graphene Oxide SPR Sensor with a Multi-Metallic Layers of Au-Ag-Au Nanostructure for Lead(II) Ion Detection,” Appl. Surf. Sci. 361, 177–184 (2016).
[Crossref]

N. F. Lokman, A. A. A. Bakar, H. F. S. Abdullah, W. B. W. A. Rahman, N. M. Huang, and M. H. Yaacob, “Highly Sensitive SPR Response of Au/Chitosan/Graphene Oxide Nanostructured Thin Films toward Pb(II) Ions,” Sens. Actuators, B 195, 459–466 (2014).
[Crossref]

Bakar, M. H. A.

A. A. Alwahib, A. R. Sadrolhosseini, M. N. An’Amt, H. N. Lim, M. H. Yaacob, M. H. A. Bakar, H. N. Ming, and M. A. Mahdi, “Reduced Graphene Oxide/Maghemite Nanocomposite for Detection of Hydrocarbon Vapor Using Surface Plasmon Resonance,” IEEE Photonics J. 8(4), 1–9 (2016).
[Crossref]

Baralkiewicz, D.

D. Barałkiewicz and J. Siepak, “Chromium, Nickel and Cobalt in Environmental Samples and Existing Legal Norms,” Polish J. Environ. Stud. 8(4), 201–208 (1999).

Baruah, S.

S. B. D. Borah, T. Bora, S. Baruah, and J. Dutta, “Heavy Metal Ion Sensing in Water Using Surface Plasmon Resonance of Metallic Nanostructures,” Groundw. Sustain. Dev. 1(1-2), 1–11 (2015).
[Crossref]

Boey, F.

X. Huang, Z. Yin, S. Wu, X. Qi, Q. He, Q. Zhang, Q. Yan, F. Boey, and H. Zhang, “Graphene-Based Materials: Synthesis, Characterization, Properties, and Applications,” Small 7(14), 1876–1902 (2011).
[Crossref]

Boonmee, C.

T. Khantaw, C. Boonmee, T. Tuntulani, and W. Ngeontae, “Selective Turn-on Fluorescence Sensor for Ag+ Using Cysteamine Capped CdS Quantum Dots: Determination of Free Ag+ in Silver Nanoparticles Solution,” Talanta 115, 849–856 (2013).
[Crossref]

Bora, T.

S. B. D. Borah, T. Bora, S. Baruah, and J. Dutta, “Heavy Metal Ion Sensing in Water Using Surface Plasmon Resonance of Metallic Nanostructures,” Groundw. Sustain. Dev. 1(1-2), 1–11 (2015).
[Crossref]

Borah, S. B. D.

S. B. D. Borah, T. Bora, S. Baruah, and J. Dutta, “Heavy Metal Ion Sensing in Water Using Surface Plasmon Resonance of Metallic Nanostructures,” Groundw. Sustain. Dev. 1(1-2), 1–11 (2015).
[Crossref]

Boukherroub, R.

L. He, Q. Pagneux, I. Larroulet, A. Y. Serrano, A. Pesquera, A. Zurutuza, D. Mandler, R. Boukherroub, and S. Szunerits, “Label-Free Femtomolar Cancer Biomarker Detection in Human Serum Using Graphene-Coated Surface Plasmon Resonance Chips,” Biosens. Bioelectron. 89, 606–611 (2017).
[Crossref]

Chen, K.

X. Zhou, K. Chen, L. Li, W. Peng, and Q. Yu, “Angle Modulated Surface Plasmon Resonance Spectrometer for Refractive Index Sensing with Enhanced Detection Resolution,” Opt. Commun. 382, 610–614 (2017).
[Crossref]

Chen, L.

D. Kong, F. Y. Yan, J. X. Xu, X. F. Guo, and L. Chen, “Cobalt (II) Ions Detection Using Carbon Dots as an Sensitive and Selective Fluorescent Probe,” RSC Adv. 6(72), 67481–67487 (2016).
[Crossref]

Chiang, H. P.

H. P. Chiang, Y. C. Wang, P. T. Leung, and W. S. Tse, “A Theoretical Model for the Temperature-dependent Sensitivity of the Optical Sensor Based on Surface Plasmon Resonance,” Opt. Commun. 188(5-6), 283–289 (2001).
[Crossref]

Chik, C. E. N. C. E.

N. A. S. Omar, Y. W. Fen, J. Abdullah, C. E. N. C. E. Chik, and M. A. Mahdi, “Development of an Optical Sensor Based on Surface Plasmon Resonance Phenomenon for Diagnosis of Dengue Virus E-Protein,” Water, Air, Soil Pollut. 20, 16–21 (2018).
[Crossref]

Choi, H. I.

H. I. Choi, J. A. Hong, M. S. Kim, S. E. Lee, S. H. Jung, P. W. Yoon, J. S. Song, and J. J. Kim, “Severe Cardiomyopathy Due to Arthroprosthetic Cobaltism: Report of Two Cases with Different Outcomes,” Cardiovasc. Toxicol. 19(1), 82–89 (2019).
[Crossref]

Clement, T. P. A.

G. P. Jeppu and T. P. A. Clement, “Modified Langmuir-Freundlich Isotherm Model for Simulating PH-Dependent Adsorption Effects,” J. Contam. Hydrol. 129-130, 46–53 (2012).
[Crossref]

Dai, X.

L. Wu, Q. You, Y. Shan, S. Gan, Y. Zhao, and X. Dai, “Few-Layer Ti 3C2Tx MXene : A Promising Surface Plasmon Resonance Biosensing Material to Enhance the Sensitivity,” Sens. Actuators, B 277, 210–215 (2018).
[Crossref]

Daniyal, W. M. E. M.

S. Saleviter, Y. W. Fen, N. A. S. Omar, W. M. E. M. Daniyal, and J. Abdullah, “Structural and Optical Studies of Cadmium Sulfide Quantum Dot-Graphene Oxide-Chitosan Nanocomposite Thin Film as a Novel SPR Spectroscopy Active Layer,” J. Nanomater. 2018, 1–8 (2018).
[Crossref]

Daniyal, W. M. E. M. M.

M. D. A. Roshidi, Y. W. Fen, W. M. E. M. M. Daniyal, N. A. S. Omar, and M. Zulholinda, “Structural and Optical Properties of Chitosan–Poly (amidoamine) Dendrimer Composite Thin Film for Potential Sensing Pb2+ using an Optical Spectroscopy,” Optik (Stuttg.) 185, 351–358 (2019).
[Crossref]

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Label-free optical spectroscopy for characterizing binding properties of highly sensitive nanocrystalline cellulose-graphene oxide based nanocomposite towards nickel ion,” Spectrochim. Acta, Part A 212, 25–31 (2019).
[Crossref]

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, S. Saleviter, and N. A. Sheh Omar, “Preparation and Characterization of Hexadecyltrimethylammonium Bromide Modified Nanocrystalline Cellulose/Graphene Oxide Composite Thin Film and Its Potential in Sensing Copper Ion Using Surface Plasmon Resonance Technique,” Optik (Stuttg.) 173, 71–77 (2018).
[Crossref]

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Exploration of Surface Plasmon Resonance for Sensing Copper Ion Based on Nanocrystalline Cellulose-Modified Thin Film,” Opt. Express 26(26), 34880–34893 (2018).
[Crossref]

Dell’Era, A.

C. Lupi, M. Pasquali, and A. Dell’Era, “Nickel and Cobalt Recycling from Lithium-Ion Batteries by Electrochemical Processes,” Waste Manage. 25(2), 215–220 (2005).
[Crossref]

Dutta, J.

S. B. D. Borah, T. Bora, S. Baruah, and J. Dutta, “Heavy Metal Ion Sensing in Water Using Surface Plasmon Resonance of Metallic Nanostructures,” Groundw. Sustain. Dev. 1(1-2), 1–11 (2015).
[Crossref]

Falamaki, C.

O. Tabasi and C. Falamaki, “Analytical Methods Recent Advancements in the Methodologies Applied for the Sensitivity Enhancement of Surface Plasmon Resonance Sensors,” Sens. Actuators, B 10(32), 3906–3925 (2018).

Fen, Y. W.

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Label-free optical spectroscopy for characterizing binding properties of highly sensitive nanocrystalline cellulose-graphene oxide based nanocomposite towards nickel ion,” Spectrochim. Acta, Part A 212, 25–31 (2019).
[Crossref]

M. D. A. Roshidi, Y. W. Fen, W. M. E. M. M. Daniyal, N. A. S. Omar, and M. Zulholinda, “Structural and Optical Properties of Chitosan–Poly (amidoamine) Dendrimer Composite Thin Film for Potential Sensing Pb2+ using an Optical Spectroscopy,” Optik (Stuttg.) 185, 351–358 (2019).
[Crossref]

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Exploration of Surface Plasmon Resonance for Sensing Copper Ion Based on Nanocrystalline Cellulose-Modified Thin Film,” Opt. Express 26(26), 34880–34893 (2018).
[Crossref]

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, S. Saleviter, and N. A. Sheh Omar, “Preparation and Characterization of Hexadecyltrimethylammonium Bromide Modified Nanocrystalline Cellulose/Graphene Oxide Composite Thin Film and Its Potential in Sensing Copper Ion Using Surface Plasmon Resonance Technique,” Optik (Stuttg.) 173, 71–77 (2018).
[Crossref]

N. A. S. Omar, Y. W. Fen, J. Abdullah, M. H. M. Zaid, and M. A. Mahdi, “Structural, Optical and Sensing Properties of CdS-NH2GO Thin Film as a Dengue Virus E-protein Sensing Material,” Optik (Stuttg.) 171, 934–940 (2018).
[Crossref]

A. A. Zainudin, Y. W. Fen, N. A. Yusof, S. H. Al-Rekabi, M. A. Mahdi, and N. A. S. Omar, “Incorporation of Surface Plasmon Resonance with Novel Valinomycin Doped Chitosan-Graphene Oxide Thin Film for Sensing Potassium Ion. Spectrochim,” Spectrochim. Acta, Part A 191, 111–115 (2018).
[Crossref]

N. A. S. Omar and Y. W. Fen, “Recent Development of SPR Spectroscopy as Potential Method for Diagnosis of Dengue Virus E-Protein,” Sens. Rev. 38(1), 106–116 (2018).
[Crossref]

S. Saleviter, Y. W. Fen, N. A. S. Omar, W. M. E. M. Daniyal, and J. Abdullah, “Structural and Optical Studies of Cadmium Sulfide Quantum Dot-Graphene Oxide-Chitosan Nanocomposite Thin Film as a Novel SPR Spectroscopy Active Layer,” J. Nanomater. 2018, 1–8 (2018).
[Crossref]

N. A. S. Omar, Y. W. Fen, J. Abdullah, C. E. N. C. E. Chik, and M. A. Mahdi, “Development of an Optical Sensor Based on Surface Plasmon Resonance Phenomenon for Diagnosis of Dengue Virus E-Protein,” Water, Air, Soil Pollut. 20, 16–21 (2018).
[Crossref]

S. Saleviter, Y. W. Fen, N. A. S. Omar, A. A. Zainudin, and N. A. Yusof, “Development of Optical Sensor for Determination of Co(II) Based on Surface Plasmon Resonance Phenomenon,” Sens. Lett. 15(10), 862–867 (2017).
[Crossref]

A. A. Zainudin, Y. W. Fen, N. A. Yusof, and N. A. S. Omar, “Structural, Optical and Sensing Properties of Ionophore Doped Graphene Based Bionanocomposite Thin Film,” Optik (Stuttg.) 144, 308–315 (2017).
[Crossref]

Y. W. Fen, W. M. M. Yunus, N. A. Yusof, N. S. Ishak, N. A. S. Omar, and A. A. Zainudin, “Preparation, Characterization and Optical Properties of Ionophore Doped Chitosan Biopolymer Thin Film and Its Potential Application for Sensing Metal Ion,” Optik (Stuttg.) 126(23), 4688–4692 (2015).
[Crossref]

Y. W. Fen, W. M. M. Yunus, Z. A. Talib, and N. A. Yusof, “Development of Surface Plasmon Resonance Sensor for Determining Zinc Ion Using Novel Active Nanolayers as Probe,” Spectrochim. Acta, Part A 134, 48–52 (2015).
[Crossref]

Y. W. Fen and W. M. M. Yunus, “Utilization of Chitosan-Based Sensor Thin Films for the Detection of Lead Ion by Surface Plasmon Resonance Optical Sensor,” IEEE Sens. J. 13(5), 1413–1418 (2013).
[Crossref]

Y. W. Fen, W. M. M. Yunus, and Z. A. Talib, “Analysis of Pb(II) Ion Sensing by Crosslinked Chitosan Thin Film Using Surface Plasmon Resonance Spectroscopy,” Optik (Stuttg.) 124(2), 126–133 (2013).
[Crossref]

Y. W. Fen and W. M. M. Yunus, “Surface Plasmon Resonance Spectroscopy as an Alternative for Sensing Heavy Metal Ions: A Review,” Sens. Rev. 33(4), 305–314 (2013).
[Crossref]

Y. W. Fen, W. M. M. Yunus, and N. A. Yusof, “Surface Plasmon Resonance Optical Sensor for Detection of Pb2+ Based on Immobilized P-Tert-Butylcalix[4]Arene-Tetrakis in Chitosan Thin Film as an Active Layer,” Sens. Actuators, B 171-172, 287–293 (2012).
[Crossref]

Y. W. Fen, W. M. M. Yunus, and Z. A. Talib, “Real-Time Monitoring of Lead Ion Interaction on Gold/Chitosan Surface Using Surface Plasmon Resonance Spectroscopy,” Indian J. Phys. 86(7), 619–623 (2012).
[Crossref]

Y. W. Fen and W. M. M. Yunus, “Characterization of the Optical Properties of Heavy Metal Ions Using Surface Plasmon Resonance Technique,” Opt. Photonics J. 01(03), 116–123 (2011).
[Crossref]

Y. W. Fen, W. M. M. Yunus, and N. A. Yusof, “Optical Properties of Cross-Linked Chitosan Thin Film for Copper Ion Detection Using Surface Plasmon Resonance Technique,” Opt. Appl. 41(4), 999–1013 (2011).

Finley, B. L.

D. J. Paustenbach, B. E. Tvermoes, K. M. Unice, B. L. Finley, and B. D. Kerger, “A Review of the Health Hazards Posed by Cobalt,” Crit. Rev. Toxicol. 43(4), 316–362 (2013).
[Crossref]

Gafur, M.

S. Yasmeen, M. Kabiraz, B. Saha, M. Qadir, M. Gafur, and S. Masum, “Chromium (VI) Ions Removal from Tannery Effluent Using Chitosan-Microcrystalline Cellulose Composite as Adsorbent,” Int. Res. J. Pure Appl. Chem. 10(4), 1–14 (2016).
[Crossref]

Gan, S.

L. Wu, Q. You, Y. Shan, S. Gan, Y. Zhao, and X. Dai, “Few-Layer Ti 3C2Tx MXene : A Promising Surface Plasmon Resonance Biosensing Material to Enhance the Sensitivity,” Sens. Actuators, B 277, 210–215 (2018).
[Crossref]

Gaur, R.

A. Paliwal, R. Gaur, A. Sharma, M. Tomar, and V. Gupta, “Sensitive Optical Biosensor Based on Surface Plasmon Resonance Using ZnO/Au Bilayered Structure,” Optik (Stuttg.) 127(19), 7642–7647 (2016).
[Crossref]

Giraldo, L.

D. P. Vargas, L. Giraldo, and J. C. Moreno-Piraján, “CO2 Adsorption on Activated Carbon Honeycomb-Monoliths: A Comparison of Langmuir and Tóth Models,” Int. J. Mol. Sci. 13(7), 8388–8397 (2012).
[Crossref]

Guo, X. F.

D. Kong, F. Y. Yan, J. X. Xu, X. F. Guo, and L. Chen, “Cobalt (II) Ions Detection Using Carbon Dots as an Sensitive and Selective Fluorescent Probe,” RSC Adv. 6(72), 67481–67487 (2016).
[Crossref]

Gupta, B.

A. Sharma, R. Jha, and B. Gupta, “Fiber-Optic Sensors Based on Surface Plasmon Resonance: A Comprehensive Review,” IEEE Sens. J. 7(8), 1118–1129 (2007).
[Crossref]

Gupta, V.

A. Paliwal, R. Gaur, A. Sharma, M. Tomar, and V. Gupta, “Sensitive Optical Biosensor Based on Surface Plasmon Resonance Using ZnO/Au Bilayered Structure,” Optik (Stuttg.) 127(19), 7642–7647 (2016).
[Crossref]

Han, L. J.

C. H. Zeng, X. T. Meng, S. S. Xu, L. J. Han, S. L. Zhong, and M. Y. Jia, “A Polymorphic Lanthanide Complex as Selective Co2+ Sensor and Luminescent Timer,” Sens. Actuators, B 221, 127–135 (2015).
[Crossref]

He, L.

L. He, Q. Pagneux, I. Larroulet, A. Y. Serrano, A. Pesquera, A. Zurutuza, D. Mandler, R. Boukherroub, and S. Szunerits, “Label-Free Femtomolar Cancer Biomarker Detection in Human Serum Using Graphene-Coated Surface Plasmon Resonance Chips,” Biosens. Bioelectron. 89, 606–611 (2017).
[Crossref]

He, Q.

X. Huang, Z. Yin, S. Wu, X. Qi, Q. He, Q. Zhang, Q. Yan, F. Boey, and H. Zhang, “Graphene-Based Materials: Synthesis, Characterization, Properties, and Applications,” Small 7(14), 1876–1902 (2011).
[Crossref]

Ho, Y. S.

Y. S. Ho, J. F. Porter, and G. McKay, “Equilibrium Isotherm Studies for the Sorption of Divalent Metal Ions onto Peat: Copper, Nickel and Lead Single Component Systems,” Water, Air, Soil Pollut. 141(1/4), 1–33 (2002).
[Crossref]

Hong, J. A.

H. I. Choi, J. A. Hong, M. S. Kim, S. E. Lee, S. H. Jung, P. W. Yoon, J. S. Song, and J. J. Kim, “Severe Cardiomyopathy Due to Arthroprosthetic Cobaltism: Report of Two Cases with Different Outcomes,” Cardiovasc. Toxicol. 19(1), 82–89 (2019).
[Crossref]

Huang, N. M.

N. F. Lokman, A. A. A. Bakar, H. F. S. Abdullah, W. B. W. A. Rahman, N. M. Huang, and M. H. Yaacob, “Highly Sensitive SPR Response of Au/Chitosan/Graphene Oxide Nanostructured Thin Films toward Pb(II) Ions,” Sens. Actuators, B 195, 459–466 (2014).
[Crossref]

Huang, X.

X. Huang, Z. Yin, S. Wu, X. Qi, Q. He, Q. Zhang, Q. Yan, F. Boey, and H. Zhang, “Graphene-Based Materials: Synthesis, Characterization, Properties, and Applications,” Small 7(14), 1876–1902 (2011).
[Crossref]

Ishak, N. S.

Y. W. Fen, W. M. M. Yunus, N. A. Yusof, N. S. Ishak, N. A. S. Omar, and A. A. Zainudin, “Preparation, Characterization and Optical Properties of Ionophore Doped Chitosan Biopolymer Thin Film and Its Potential Application for Sensing Metal Ion,” Optik (Stuttg.) 126(23), 4688–4692 (2015).
[Crossref]

Issa, R.

M. H. M. Zaid, J. Abdullah, N. A. Yusof, Y. Sulaiman, H. Wasoh, M. F. M. Noh, and R. Issa, “PNA Biosensor Based on Reduced Graphene Oxide/Water Soluble Quantum Dots for the Detection of Mycobacterium Tuberculosis,” Sens. Actuators, B 241, 1024–1034 (2017).
[Crossref]

Jeong, U.

U. Jeong, H. H. Shin, and Y. H. Kim, “Functionalized Magnetic Core-shell Fe@SiO2 Nanoparticles as Recoverable Colorimetric Sensor for Co2+ Ion,” Chem. Eng. J. 281, 428–433 (2015).
[Crossref]

Jeppu, G. P.

G. P. Jeppu and T. P. A. Clement, “Modified Langmuir-Freundlich Isotherm Model for Simulating PH-Dependent Adsorption Effects,” J. Contam. Hydrol. 129-130, 46–53 (2012).
[Crossref]

Jha, R.

A. Sharma, R. Jha, and B. Gupta, “Fiber-Optic Sensors Based on Surface Plasmon Resonance: A Comprehensive Review,” IEEE Sens. J. 7(8), 1118–1129 (2007).
[Crossref]

Jia, M. Y.

C. H. Zeng, X. T. Meng, S. S. Xu, L. J. Han, S. L. Zhong, and M. Y. Jia, “A Polymorphic Lanthanide Complex as Selective Co2+ Sensor and Luminescent Timer,” Sens. Actuators, B 221, 127–135 (2015).
[Crossref]

Jung, S. H.

H. I. Choi, J. A. Hong, M. S. Kim, S. E. Lee, S. H. Jung, P. W. Yoon, J. S. Song, and J. J. Kim, “Severe Cardiomyopathy Due to Arthroprosthetic Cobaltism: Report of Two Cases with Different Outcomes,” Cardiovasc. Toxicol. 19(1), 82–89 (2019).
[Crossref]

Kabiraz, M.

S. Yasmeen, M. Kabiraz, B. Saha, M. Qadir, M. Gafur, and S. Masum, “Chromium (VI) Ions Removal from Tannery Effluent Using Chitosan-Microcrystalline Cellulose Composite as Adsorbent,” Int. Res. J. Pure Appl. Chem. 10(4), 1–14 (2016).
[Crossref]

Kailasa, S. K.

U. B. Patel, V. N. Mehta, A. K. Mungara, and S. K. Kailasa, “4-Aminothiophenol Functionalized Gold Nanoparticles as Colorimetric Sensors for the Detection of Cobalt Using UV–Visible Spectrometry,” Res. Chem. Intermed. 39(2), 771–779 (2013).
[Crossref]

V. N. Mehta, A. K. Mungara, and S. K. Kailasa, “Dopamine Dithiocarbamate Functionalized Silver Nanoparticles as Colorimetric Sensors for the Detection of Cobalt Ion,” Anal. Methods 5(7), 1818–1822 (2013).
[Crossref]

Kamaraj, M.

P. Kanmani, J. Aravind, M. Kamaraj, P. Sureshbabu, and S. Karthikeyan, “Bioresource Technology Environmental Applications of Chitosan and Cellulosic Biopolymers : A Comprehensive Outlook,” Bioresour. Technol. 242, 295–303 (2017).
[Crossref]

Kamari, H. M.

A. R. Sadrolhosseini, M. Naseri, and H. M. Kamari, “Surface Plasmon Resonance Sensor for Detecting of Arsenic in Aqueous Solution Using Polypyrrole-Chitosan-Cobalt Ferrite Nanoparticles Composite Layer,” Opt. Commun. 383, 132–137 (2017).
[Crossref]

Kamaruddin, N.

N. Kamaruddin, A. A. Bakar, N. Mobarak, M. S. Zan, and N. Arsad, “Binding Affinity of a Highly Sensitive Au/Ag/Au/Chitosan-Graphene Oxide Sensor Based on Direct Detection of Pb2+ and Hg2+ Ions,” Sensors 17(10), 2277 (2017).
[Crossref]

Kamaruddin, N. H.

N. H. Kamaruddin, A. A. A. Bakar, M. H. Yaacob, M. A. Mahdi, M. S. D. Zan, and S. Shaari, “Enhancement of Chitosan-Graphene Oxide SPR Sensor with a Multi-Metallic Layers of Au-Ag-Au Nanostructure for Lead(II) Ion Detection,” Appl. Surf. Sci. 361, 177–184 (2016).
[Crossref]

Kanmani, P.

P. Kanmani, J. Aravind, M. Kamaraj, P. Sureshbabu, and S. Karthikeyan, “Bioresource Technology Environmental Applications of Chitosan and Cellulosic Biopolymers : A Comprehensive Outlook,” Bioresour. Technol. 242, 295–303 (2017).
[Crossref]

Karthikeyan, S.

P. Kanmani, J. Aravind, M. Kamaraj, P. Sureshbabu, and S. Karthikeyan, “Bioresource Technology Environmental Applications of Chitosan and Cellulosic Biopolymers : A Comprehensive Outlook,” Bioresour. Technol. 242, 295–303 (2017).
[Crossref]

Kaur, N.

H. Sharma, A. Singh, N. Kaur, and N. Singh, “ZnO-Based Imine-Linked Coupled Biocompatible Chemosensor for Nanomolar Detection of Co2+,” ACS Sustainable Chem. Eng. 1(12), 1600–1608 (2013).
[Crossref]

Kerger, B. D.

D. J. Paustenbach, B. E. Tvermoes, K. M. Unice, B. L. Finley, and B. D. Kerger, “A Review of the Health Hazards Posed by Cobalt,” Crit. Rev. Toxicol. 43(4), 316–362 (2013).
[Crossref]

Khantaw, T.

T. Khantaw, C. Boonmee, T. Tuntulani, and W. Ngeontae, “Selective Turn-on Fluorescence Sensor for Ag+ Using Cysteamine Capped CdS Quantum Dots: Determination of Free Ag+ in Silver Nanoparticles Solution,” Talanta 115, 849–856 (2013).
[Crossref]

Kim, J. J.

H. I. Choi, J. A. Hong, M. S. Kim, S. E. Lee, S. H. Jung, P. W. Yoon, J. S. Song, and J. J. Kim, “Severe Cardiomyopathy Due to Arthroprosthetic Cobaltism: Report of Two Cases with Different Outcomes,” Cardiovasc. Toxicol. 19(1), 82–89 (2019).
[Crossref]

Kim, M. S.

H. I. Choi, J. A. Hong, M. S. Kim, S. E. Lee, S. H. Jung, P. W. Yoon, J. S. Song, and J. J. Kim, “Severe Cardiomyopathy Due to Arthroprosthetic Cobaltism: Report of Two Cases with Different Outcomes,” Cardiovasc. Toxicol. 19(1), 82–89 (2019).
[Crossref]

Kim, Y. H.

U. Jeong, H. H. Shin, and Y. H. Kim, “Functionalized Magnetic Core-shell Fe@SiO2 Nanoparticles as Recoverable Colorimetric Sensor for Co2+ Ion,” Chem. Eng. J. 281, 428–433 (2015).
[Crossref]

Kong, D.

D. Kong, F. Y. Yan, J. X. Xu, X. F. Guo, and L. Chen, “Cobalt (II) Ions Detection Using Carbon Dots as an Sensitive and Selective Fluorescent Probe,” RSC Adv. 6(72), 67481–67487 (2016).
[Crossref]

Kumar, M. N. R.

M. N. R. Kumar, “A Review of Chitin and Chitosan Applications. Reactive and Functional Polymers,” React. Funct. Polym. 46(1), 1–27 (2000).
[Crossref]

Larroulet, I.

L. He, Q. Pagneux, I. Larroulet, A. Y. Serrano, A. Pesquera, A. Zurutuza, D. Mandler, R. Boukherroub, and S. Szunerits, “Label-Free Femtomolar Cancer Biomarker Detection in Human Serum Using Graphene-Coated Surface Plasmon Resonance Chips,” Biosens. Bioelectron. 89, 606–611 (2017).
[Crossref]

Lauwerys, R.

R. Lauwerys and D. Lison, “Health Risks Associated with Cobalt Exposure An Overview,” Sci. Total Environ. 150(1-3), 1–6 (1994).
[Crossref]

Lee, S. E.

H. I. Choi, J. A. Hong, M. S. Kim, S. E. Lee, S. H. Jung, P. W. Yoon, J. S. Song, and J. J. Kim, “Severe Cardiomyopathy Due to Arthroprosthetic Cobaltism: Report of Two Cases with Different Outcomes,” Cardiovasc. Toxicol. 19(1), 82–89 (2019).
[Crossref]

Leung, P. T.

H. P. Chiang, Y. C. Wang, P. T. Leung, and W. S. Tse, “A Theoretical Model for the Temperature-dependent Sensitivity of the Optical Sensor Based on Surface Plasmon Resonance,” Opt. Commun. 188(5-6), 283–289 (2001).
[Crossref]

Li, K.

K. Li, W. Zhou, and S. Zeng, “Optical Micro/Nanofiber-Based Localized Surface Plasmon Resonance Biosensors: Fiber Diameter Dependence,” Sensors 18(10), 3295 (2018).
[Crossref]

Li, L.

X. Zhou, K. Chen, L. Li, W. Peng, and Q. Yu, “Angle Modulated Surface Plasmon Resonance Spectrometer for Refractive Index Sensing with Enhanced Detection Resolution,” Opt. Commun. 382, 610–614 (2017).
[Crossref]

Liao, R.

B. Yu, J. Xu, J. H. Liu, S. T. Yang, J. Luo, Q. Zhou, J. Wan, R. Liao, H. Wang, and Y. Liu, “Adsorption Behavior of Copper Ions on Graphene Oxide-Chitosan Aerogel,” J. Environ. Chem. Eng. 1(4), 1044–1050 (2013).
[Crossref]

Lim, H. N.

A. A. Alwahib, A. R. Sadrolhosseini, M. N. An’Amt, H. N. Lim, M. H. Yaacob, M. H. A. Bakar, H. N. Ming, and M. A. Mahdi, “Reduced Graphene Oxide/Maghemite Nanocomposite for Detection of Hydrocarbon Vapor Using Surface Plasmon Resonance,” IEEE Photonics J. 8(4), 1–9 (2016).
[Crossref]

Lison, D.

R. Lauwerys and D. Lison, “Health Risks Associated with Cobalt Exposure An Overview,” Sci. Total Environ. 150(1-3), 1–6 (1994).
[Crossref]

Liu, J. H.

B. Yu, J. Xu, J. H. Liu, S. T. Yang, J. Luo, Q. Zhou, J. Wan, R. Liao, H. Wang, and Y. Liu, “Adsorption Behavior of Copper Ions on Graphene Oxide-Chitosan Aerogel,” J. Environ. Chem. Eng. 1(4), 1044–1050 (2013).
[Crossref]

Liu, S.

X. Luo, J. Zeng, S. Liu, and L. Zhang, “Bioresource Technology an Effective and Recyclable Adsorbent for the Removal of Heavy Metal Ions from Aqueous System : Magnetic Chitosan/Cellulose Microspheres,” Bioresour. Technol. 194, 403–406 (2015).
[Crossref]

S. Liu, W. Na, S. Pang, and X. Su, “Fluorescence Detection of Pb2+based on the DNA Sequence Functionalized CdS Quantum Dots,” Biosens. Bioelectron. 58, 17–21 (2014).
[Crossref]

Liu, Y.

B. Yu, J. Xu, J. H. Liu, S. T. Yang, J. Luo, Q. Zhou, J. Wan, R. Liao, H. Wang, and Y. Liu, “Adsorption Behavior of Copper Ions on Graphene Oxide-Chitosan Aerogel,” J. Environ. Chem. Eng. 1(4), 1044–1050 (2013).
[Crossref]

Liu, Y. Q.

M. Zhang, Y. Q. Liu, and B. C. Ye, “Colorimetric Assay for Parallel Detection of Cd2+, Ni2+ and Co2+ Using Peptide-Modified Gold Nanoparticles,” Analyst 137(3), 601–607 (2012).
[Crossref]

Lokman, N. F.

N. F. Lokman, A. A. A. Bakar, H. F. S. Abdullah, W. B. W. A. Rahman, N. M. Huang, and M. H. Yaacob, “Highly Sensitive SPR Response of Au/Chitosan/Graphene Oxide Nanostructured Thin Films toward Pb(II) Ions,” Sens. Actuators, B 195, 459–466 (2014).
[Crossref]

Luo, J.

B. Yu, J. Xu, J. H. Liu, S. T. Yang, J. Luo, Q. Zhou, J. Wan, R. Liao, H. Wang, and Y. Liu, “Adsorption Behavior of Copper Ions on Graphene Oxide-Chitosan Aerogel,” J. Environ. Chem. Eng. 1(4), 1044–1050 (2013).
[Crossref]

Luo, X.

X. Luo, J. Zeng, S. Liu, and L. Zhang, “Bioresource Technology an Effective and Recyclable Adsorbent for the Removal of Heavy Metal Ions from Aqueous System : Magnetic Chitosan/Cellulose Microspheres,” Bioresour. Technol. 194, 403–406 (2015).
[Crossref]

Lupi, C.

C. Lupi, M. Pasquali, and A. Dell’Era, “Nickel and Cobalt Recycling from Lithium-Ion Batteries by Electrochemical Processes,” Waste Manage. 25(2), 215–220 (2005).
[Crossref]

Mahdi, M. A.

N. A. S. Omar, Y. W. Fen, J. Abdullah, M. H. M. Zaid, and M. A. Mahdi, “Structural, Optical and Sensing Properties of CdS-NH2GO Thin Film as a Dengue Virus E-protein Sensing Material,” Optik (Stuttg.) 171, 934–940 (2018).
[Crossref]

A. A. Zainudin, Y. W. Fen, N. A. Yusof, S. H. Al-Rekabi, M. A. Mahdi, and N. A. S. Omar, “Incorporation of Surface Plasmon Resonance with Novel Valinomycin Doped Chitosan-Graphene Oxide Thin Film for Sensing Potassium Ion. Spectrochim,” Spectrochim. Acta, Part A 191, 111–115 (2018).
[Crossref]

N. A. S. Omar, Y. W. Fen, J. Abdullah, C. E. N. C. E. Chik, and M. A. Mahdi, “Development of an Optical Sensor Based on Surface Plasmon Resonance Phenomenon for Diagnosis of Dengue Virus E-Protein,” Water, Air, Soil Pollut. 20, 16–21 (2018).
[Crossref]

A. A. Alwahib, A. R. Sadrolhosseini, M. N. An’Amt, H. N. Lim, M. H. Yaacob, M. H. A. Bakar, H. N. Ming, and M. A. Mahdi, “Reduced Graphene Oxide/Maghemite Nanocomposite for Detection of Hydrocarbon Vapor Using Surface Plasmon Resonance,” IEEE Photonics J. 8(4), 1–9 (2016).
[Crossref]

N. H. Kamaruddin, A. A. A. Bakar, M. H. Yaacob, M. A. Mahdi, M. S. D. Zan, and S. Shaari, “Enhancement of Chitosan-Graphene Oxide SPR Sensor with a Multi-Metallic Layers of Au-Ag-Au Nanostructure for Lead(II) Ion Detection,” Appl. Surf. Sci. 361, 177–184 (2016).
[Crossref]

Mandler, D.

L. He, Q. Pagneux, I. Larroulet, A. Y. Serrano, A. Pesquera, A. Zurutuza, D. Mandler, R. Boukherroub, and S. Szunerits, “Label-Free Femtomolar Cancer Biomarker Detection in Human Serum Using Graphene-Coated Surface Plasmon Resonance Chips,” Biosens. Bioelectron. 89, 606–611 (2017).
[Crossref]

Manheim, F. T.

F. T. Manheim, “Marine cobalt resources,” Science 232(4750), 600–608 (1986).
[Crossref]

Masum, S.

S. Yasmeen, M. Kabiraz, B. Saha, M. Qadir, M. Gafur, and S. Masum, “Chromium (VI) Ions Removal from Tannery Effluent Using Chitosan-Microcrystalline Cellulose Composite as Adsorbent,” Int. Res. J. Pure Appl. Chem. 10(4), 1–14 (2016).
[Crossref]

McKay, G.

Y. S. Ho, J. F. Porter, and G. McKay, “Equilibrium Isotherm Studies for the Sorption of Divalent Metal Ions onto Peat: Copper, Nickel and Lead Single Component Systems,” Water, Air, Soil Pollut. 141(1/4), 1–33 (2002).
[Crossref]

Mehta, V. N.

U. B. Patel, V. N. Mehta, A. K. Mungara, and S. K. Kailasa, “4-Aminothiophenol Functionalized Gold Nanoparticles as Colorimetric Sensors for the Detection of Cobalt Using UV–Visible Spectrometry,” Res. Chem. Intermed. 39(2), 771–779 (2013).
[Crossref]

V. N. Mehta, A. K. Mungara, and S. K. Kailasa, “Dopamine Dithiocarbamate Functionalized Silver Nanoparticles as Colorimetric Sensors for the Detection of Cobalt Ion,” Anal. Methods 5(7), 1818–1822 (2013).
[Crossref]

Meng, X. T.

C. H. Zeng, X. T. Meng, S. S. Xu, L. J. Han, S. L. Zhong, and M. Y. Jia, “A Polymorphic Lanthanide Complex as Selective Co2+ Sensor and Luminescent Timer,” Sens. Actuators, B 221, 127–135 (2015).
[Crossref]

Ming, H. N.

A. A. Alwahib, A. R. Sadrolhosseini, M. N. An’Amt, H. N. Lim, M. H. Yaacob, M. H. A. Bakar, H. N. Ming, and M. A. Mahdi, “Reduced Graphene Oxide/Maghemite Nanocomposite for Detection of Hydrocarbon Vapor Using Surface Plasmon Resonance,” IEEE Photonics J. 8(4), 1–9 (2016).
[Crossref]

Mobarak, N.

N. Kamaruddin, A. A. Bakar, N. Mobarak, M. S. Zan, and N. Arsad, “Binding Affinity of a Highly Sensitive Au/Ag/Au/Chitosan-Graphene Oxide Sensor Based on Direct Detection of Pb2+ and Hg2+ Ions,” Sensors 17(10), 2277 (2017).
[Crossref]

Mohammadi, H.

M. Asgari, H. Anisi, H. Mohammadi, and S. Sadighi, “Designing a Commercial Scale Pressure Swing Adsorber for Hydrogen Purification,” Pet. Coal. 56(5), 552–561 (2014).

Moreno-Piraján, J. C.

D. P. Vargas, L. Giraldo, and J. C. Moreno-Piraján, “CO2 Adsorption on Activated Carbon Honeycomb-Monoliths: A Comparison of Langmuir and Tóth Models,” Int. J. Mol. Sci. 13(7), 8388–8397 (2012).
[Crossref]

Mungara, A. K.

V. N. Mehta, A. K. Mungara, and S. K. Kailasa, “Dopamine Dithiocarbamate Functionalized Silver Nanoparticles as Colorimetric Sensors for the Detection of Cobalt Ion,” Anal. Methods 5(7), 1818–1822 (2013).
[Crossref]

U. B. Patel, V. N. Mehta, A. K. Mungara, and S. K. Kailasa, “4-Aminothiophenol Functionalized Gold Nanoparticles as Colorimetric Sensors for the Detection of Cobalt Using UV–Visible Spectrometry,” Res. Chem. Intermed. 39(2), 771–779 (2013).
[Crossref]

Na, W.

S. Liu, W. Na, S. Pang, and X. Su, “Fluorescence Detection of Pb2+based on the DNA Sequence Functionalized CdS Quantum Dots,” Biosens. Bioelectron. 58, 17–21 (2014).
[Crossref]

Naseri, M.

A. R. Sadrolhosseini, M. Naseri, and H. M. Kamari, “Surface Plasmon Resonance Sensor for Detecting of Arsenic in Aqueous Solution Using Polypyrrole-Chitosan-Cobalt Ferrite Nanoparticles Composite Layer,” Opt. Commun. 383, 132–137 (2017).
[Crossref]

Ngeontae, W.

T. Khantaw, C. Boonmee, T. Tuntulani, and W. Ngeontae, “Selective Turn-on Fluorescence Sensor for Ag+ Using Cysteamine Capped CdS Quantum Dots: Determination of Free Ag+ in Silver Nanoparticles Solution,” Talanta 115, 849–856 (2013).
[Crossref]

Noh, M. F. M.

M. H. M. Zaid, J. Abdullah, N. A. Yusof, Y. Sulaiman, H. Wasoh, M. F. M. Noh, and R. Issa, “PNA Biosensor Based on Reduced Graphene Oxide/Water Soluble Quantum Dots for the Detection of Mycobacterium Tuberculosis,” Sens. Actuators, B 241, 1024–1034 (2017).
[Crossref]

Omar, N. A. S.

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Label-free optical spectroscopy for characterizing binding properties of highly sensitive nanocrystalline cellulose-graphene oxide based nanocomposite towards nickel ion,” Spectrochim. Acta, Part A 212, 25–31 (2019).
[Crossref]

M. D. A. Roshidi, Y. W. Fen, W. M. E. M. M. Daniyal, N. A. S. Omar, and M. Zulholinda, “Structural and Optical Properties of Chitosan–Poly (amidoamine) Dendrimer Composite Thin Film for Potential Sensing Pb2+ using an Optical Spectroscopy,” Optik (Stuttg.) 185, 351–358 (2019).
[Crossref]

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Exploration of Surface Plasmon Resonance for Sensing Copper Ion Based on Nanocrystalline Cellulose-Modified Thin Film,” Opt. Express 26(26), 34880–34893 (2018).
[Crossref]

A. A. Zainudin, Y. W. Fen, N. A. Yusof, S. H. Al-Rekabi, M. A. Mahdi, and N. A. S. Omar, “Incorporation of Surface Plasmon Resonance with Novel Valinomycin Doped Chitosan-Graphene Oxide Thin Film for Sensing Potassium Ion. Spectrochim,” Spectrochim. Acta, Part A 191, 111–115 (2018).
[Crossref]

N. A. S. Omar, Y. W. Fen, J. Abdullah, M. H. M. Zaid, and M. A. Mahdi, “Structural, Optical and Sensing Properties of CdS-NH2GO Thin Film as a Dengue Virus E-protein Sensing Material,” Optik (Stuttg.) 171, 934–940 (2018).
[Crossref]

N. A. S. Omar and Y. W. Fen, “Recent Development of SPR Spectroscopy as Potential Method for Diagnosis of Dengue Virus E-Protein,” Sens. Rev. 38(1), 106–116 (2018).
[Crossref]

S. Saleviter, Y. W. Fen, N. A. S. Omar, W. M. E. M. Daniyal, and J. Abdullah, “Structural and Optical Studies of Cadmium Sulfide Quantum Dot-Graphene Oxide-Chitosan Nanocomposite Thin Film as a Novel SPR Spectroscopy Active Layer,” J. Nanomater. 2018, 1–8 (2018).
[Crossref]

N. A. S. Omar, Y. W. Fen, J. Abdullah, C. E. N. C. E. Chik, and M. A. Mahdi, “Development of an Optical Sensor Based on Surface Plasmon Resonance Phenomenon for Diagnosis of Dengue Virus E-Protein,” Water, Air, Soil Pollut. 20, 16–21 (2018).
[Crossref]

S. Saleviter, Y. W. Fen, N. A. S. Omar, A. A. Zainudin, and N. A. Yusof, “Development of Optical Sensor for Determination of Co(II) Based on Surface Plasmon Resonance Phenomenon,” Sens. Lett. 15(10), 862–867 (2017).
[Crossref]

A. A. Zainudin, Y. W. Fen, N. A. Yusof, and N. A. S. Omar, “Structural, Optical and Sensing Properties of Ionophore Doped Graphene Based Bionanocomposite Thin Film,” Optik (Stuttg.) 144, 308–315 (2017).
[Crossref]

Y. W. Fen, W. M. M. Yunus, N. A. Yusof, N. S. Ishak, N. A. S. Omar, and A. A. Zainudin, “Preparation, Characterization and Optical Properties of Ionophore Doped Chitosan Biopolymer Thin Film and Its Potential Application for Sensing Metal Ion,” Optik (Stuttg.) 126(23), 4688–4692 (2015).
[Crossref]

Pagneux, Q.

L. He, Q. Pagneux, I. Larroulet, A. Y. Serrano, A. Pesquera, A. Zurutuza, D. Mandler, R. Boukherroub, and S. Szunerits, “Label-Free Femtomolar Cancer Biomarker Detection in Human Serum Using Graphene-Coated Surface Plasmon Resonance Chips,” Biosens. Bioelectron. 89, 606–611 (2017).
[Crossref]

Paliwal, A.

A. Paliwal, R. Gaur, A. Sharma, M. Tomar, and V. Gupta, “Sensitive Optical Biosensor Based on Surface Plasmon Resonance Using ZnO/Au Bilayered Structure,” Optik (Stuttg.) 127(19), 7642–7647 (2016).
[Crossref]

Pang, S.

S. Liu, W. Na, S. Pang, and X. Su, “Fluorescence Detection of Pb2+based on the DNA Sequence Functionalized CdS Quantum Dots,” Biosens. Bioelectron. 58, 17–21 (2014).
[Crossref]

Pasquali, M.

C. Lupi, M. Pasquali, and A. Dell’Era, “Nickel and Cobalt Recycling from Lithium-Ion Batteries by Electrochemical Processes,” Waste Manage. 25(2), 215–220 (2005).
[Crossref]

Patel, U. B.

U. B. Patel, V. N. Mehta, A. K. Mungara, and S. K. Kailasa, “4-Aminothiophenol Functionalized Gold Nanoparticles as Colorimetric Sensors for the Detection of Cobalt Using UV–Visible Spectrometry,” Res. Chem. Intermed. 39(2), 771–779 (2013).
[Crossref]

Paustenbach, D. J.

D. J. Paustenbach, B. E. Tvermoes, K. M. Unice, B. L. Finley, and B. D. Kerger, “A Review of the Health Hazards Posed by Cobalt,” Crit. Rev. Toxicol. 43(4), 316–362 (2013).
[Crossref]

Peng, W.

X. Zhou, K. Chen, L. Li, W. Peng, and Q. Yu, “Angle Modulated Surface Plasmon Resonance Spectrometer for Refractive Index Sensing with Enhanced Detection Resolution,” Opt. Commun. 382, 610–614 (2017).
[Crossref]

Pesquera, A.

L. He, Q. Pagneux, I. Larroulet, A. Y. Serrano, A. Pesquera, A. Zurutuza, D. Mandler, R. Boukherroub, and S. Szunerits, “Label-Free Femtomolar Cancer Biomarker Detection in Human Serum Using Graphene-Coated Surface Plasmon Resonance Chips,” Biosens. Bioelectron. 89, 606–611 (2017).
[Crossref]

Planecka, A.

A. Sionkowska and A. Płanecka, “Surface Properties of Thin Films Based on the Mixtures of Chitosan and Silk Fibroin,” J. Mol. Liq. 186, 157–162 (2013).
[Crossref]

Pluchery, O.

O. Pluchery, R. Vayron, and K. M. Van, “Laboratory Experiments for Exploring the Surface Plasmon Resonance,” Eur. J. Phys. 32(2), 585–599 (2011).
[Crossref]

Porter, J. F.

Y. S. Ho, J. F. Porter, and G. McKay, “Equilibrium Isotherm Studies for the Sorption of Divalent Metal Ions onto Peat: Copper, Nickel and Lead Single Component Systems,” Water, Air, Soil Pollut. 141(1/4), 1–33 (2002).
[Crossref]

Qadir, M.

S. Yasmeen, M. Kabiraz, B. Saha, M. Qadir, M. Gafur, and S. Masum, “Chromium (VI) Ions Removal from Tannery Effluent Using Chitosan-Microcrystalline Cellulose Composite as Adsorbent,” Int. Res. J. Pure Appl. Chem. 10(4), 1–14 (2016).
[Crossref]

Qi, X.

X. Huang, Z. Yin, S. Wu, X. Qi, Q. He, Q. Zhang, Q. Yan, F. Boey, and H. Zhang, “Graphene-Based Materials: Synthesis, Characterization, Properties, and Applications,” Small 7(14), 1876–1902 (2011).
[Crossref]

Rahman, W. B. W. A.

N. F. Lokman, A. A. A. Bakar, H. F. S. Abdullah, W. B. W. A. Rahman, N. M. Huang, and M. H. Yaacob, “Highly Sensitive SPR Response of Au/Chitosan/Graphene Oxide Nanostructured Thin Films toward Pb(II) Ions,” Sens. Actuators, B 195, 459–466 (2014).
[Crossref]

Roshidi, M. D. A.

M. D. A. Roshidi, Y. W. Fen, W. M. E. M. M. Daniyal, N. A. S. Omar, and M. Zulholinda, “Structural and Optical Properties of Chitosan–Poly (amidoamine) Dendrimer Composite Thin Film for Potential Sensing Pb2+ using an Optical Spectroscopy,” Optik (Stuttg.) 185, 351–358 (2019).
[Crossref]

Sadighi, S.

M. Asgari, H. Anisi, H. Mohammadi, and S. Sadighi, “Designing a Commercial Scale Pressure Swing Adsorber for Hydrogen Purification,” Pet. Coal. 56(5), 552–561 (2014).

Sadrolhosseini, A. R.

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Label-free optical spectroscopy for characterizing binding properties of highly sensitive nanocrystalline cellulose-graphene oxide based nanocomposite towards nickel ion,” Spectrochim. Acta, Part A 212, 25–31 (2019).
[Crossref]

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Exploration of Surface Plasmon Resonance for Sensing Copper Ion Based on Nanocrystalline Cellulose-Modified Thin Film,” Opt. Express 26(26), 34880–34893 (2018).
[Crossref]

A. R. Sadrolhosseini, M. Naseri, and H. M. Kamari, “Surface Plasmon Resonance Sensor for Detecting of Arsenic in Aqueous Solution Using Polypyrrole-Chitosan-Cobalt Ferrite Nanoparticles Composite Layer,” Opt. Commun. 383, 132–137 (2017).
[Crossref]

A. A. Alwahib, A. R. Sadrolhosseini, M. N. An’Amt, H. N. Lim, M. H. Yaacob, M. H. A. Bakar, H. N. Ming, and M. A. Mahdi, “Reduced Graphene Oxide/Maghemite Nanocomposite for Detection of Hydrocarbon Vapor Using Surface Plasmon Resonance,” IEEE Photonics J. 8(4), 1–9 (2016).
[Crossref]

Saha, B.

S. Yasmeen, M. Kabiraz, B. Saha, M. Qadir, M. Gafur, and S. Masum, “Chromium (VI) Ions Removal from Tannery Effluent Using Chitosan-Microcrystalline Cellulose Composite as Adsorbent,” Int. Res. J. Pure Appl. Chem. 10(4), 1–14 (2016).
[Crossref]

Saleviter, S.

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Label-free optical spectroscopy for characterizing binding properties of highly sensitive nanocrystalline cellulose-graphene oxide based nanocomposite towards nickel ion,” Spectrochim. Acta, Part A 212, 25–31 (2019).
[Crossref]

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, S. Saleviter, and N. A. Sheh Omar, “Preparation and Characterization of Hexadecyltrimethylammonium Bromide Modified Nanocrystalline Cellulose/Graphene Oxide Composite Thin Film and Its Potential in Sensing Copper Ion Using Surface Plasmon Resonance Technique,” Optik (Stuttg.) 173, 71–77 (2018).
[Crossref]

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Exploration of Surface Plasmon Resonance for Sensing Copper Ion Based on Nanocrystalline Cellulose-Modified Thin Film,” Opt. Express 26(26), 34880–34893 (2018).
[Crossref]

S. Saleviter, Y. W. Fen, N. A. S. Omar, W. M. E. M. Daniyal, and J. Abdullah, “Structural and Optical Studies of Cadmium Sulfide Quantum Dot-Graphene Oxide-Chitosan Nanocomposite Thin Film as a Novel SPR Spectroscopy Active Layer,” J. Nanomater. 2018, 1–8 (2018).
[Crossref]

S. Saleviter, Y. W. Fen, N. A. S. Omar, A. A. Zainudin, and N. A. Yusof, “Development of Optical Sensor for Determination of Co(II) Based on Surface Plasmon Resonance Phenomenon,” Sens. Lett. 15(10), 862–867 (2017).
[Crossref]

Serrano, A. Y.

L. He, Q. Pagneux, I. Larroulet, A. Y. Serrano, A. Pesquera, A. Zurutuza, D. Mandler, R. Boukherroub, and S. Szunerits, “Label-Free Femtomolar Cancer Biomarker Detection in Human Serum Using Graphene-Coated Surface Plasmon Resonance Chips,” Biosens. Bioelectron. 89, 606–611 (2017).
[Crossref]

Shaari, S.

N. H. Kamaruddin, A. A. A. Bakar, M. H. Yaacob, M. A. Mahdi, M. S. D. Zan, and S. Shaari, “Enhancement of Chitosan-Graphene Oxide SPR Sensor with a Multi-Metallic Layers of Au-Ag-Au Nanostructure for Lead(II) Ion Detection,” Appl. Surf. Sci. 361, 177–184 (2016).
[Crossref]

Shan, Y.

L. Wu, Q. You, Y. Shan, S. Gan, Y. Zhao, and X. Dai, “Few-Layer Ti 3C2Tx MXene : A Promising Surface Plasmon Resonance Biosensing Material to Enhance the Sensitivity,” Sens. Actuators, B 277, 210–215 (2018).
[Crossref]

Sharma, A.

A. Paliwal, R. Gaur, A. Sharma, M. Tomar, and V. Gupta, “Sensitive Optical Biosensor Based on Surface Plasmon Resonance Using ZnO/Au Bilayered Structure,” Optik (Stuttg.) 127(19), 7642–7647 (2016).
[Crossref]

A. Sharma, R. Jha, and B. Gupta, “Fiber-Optic Sensors Based on Surface Plasmon Resonance: A Comprehensive Review,” IEEE Sens. J. 7(8), 1118–1129 (2007).
[Crossref]

Sharma, H.

H. Sharma, A. Singh, N. Kaur, and N. Singh, “ZnO-Based Imine-Linked Coupled Biocompatible Chemosensor for Nanomolar Detection of Co2+,” ACS Sustainable Chem. Eng. 1(12), 1600–1608 (2013).
[Crossref]

Sheh Omar, N. A.

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, S. Saleviter, and N. A. Sheh Omar, “Preparation and Characterization of Hexadecyltrimethylammonium Bromide Modified Nanocrystalline Cellulose/Graphene Oxide Composite Thin Film and Its Potential in Sensing Copper Ion Using Surface Plasmon Resonance Technique,” Optik (Stuttg.) 173, 71–77 (2018).
[Crossref]

Shin, H. H.

U. Jeong, H. H. Shin, and Y. H. Kim, “Functionalized Magnetic Core-shell Fe@SiO2 Nanoparticles as Recoverable Colorimetric Sensor for Co2+ Ion,” Chem. Eng. J. 281, 428–433 (2015).
[Crossref]

Siepak, J.

D. Barałkiewicz and J. Siepak, “Chromium, Nickel and Cobalt in Environmental Samples and Existing Legal Norms,” Polish J. Environ. Stud. 8(4), 201–208 (1999).

Singh, A.

H. Sharma, A. Singh, N. Kaur, and N. Singh, “ZnO-Based Imine-Linked Coupled Biocompatible Chemosensor for Nanomolar Detection of Co2+,” ACS Sustainable Chem. Eng. 1(12), 1600–1608 (2013).
[Crossref]

Singh, N.

H. Sharma, A. Singh, N. Kaur, and N. Singh, “ZnO-Based Imine-Linked Coupled Biocompatible Chemosensor for Nanomolar Detection of Co2+,” ACS Sustainable Chem. Eng. 1(12), 1600–1608 (2013).
[Crossref]

Singh, P.

P. Singh, “SPR Biosensors: Historical Perspectives and Current Challenges,” Sens. Actuators, B 229, 110–130 (2016).
[Crossref]

Sionkowska, A.

A. Sionkowska and A. Płanecka, “Surface Properties of Thin Films Based on the Mixtures of Chitosan and Silk Fibroin,” J. Mol. Liq. 186, 157–162 (2013).
[Crossref]

Song, J. S.

H. I. Choi, J. A. Hong, M. S. Kim, S. E. Lee, S. H. Jung, P. W. Yoon, J. S. Song, and J. J. Kim, “Severe Cardiomyopathy Due to Arthroprosthetic Cobaltism: Report of Two Cases with Different Outcomes,” Cardiovasc. Toxicol. 19(1), 82–89 (2019).
[Crossref]

Su, X.

S. Liu, W. Na, S. Pang, and X. Su, “Fluorescence Detection of Pb2+based on the DNA Sequence Functionalized CdS Quantum Dots,” Biosens. Bioelectron. 58, 17–21 (2014).
[Crossref]

Sulaiman, Y.

M. H. M. Zaid, J. Abdullah, N. A. Yusof, Y. Sulaiman, H. Wasoh, M. F. M. Noh, and R. Issa, “PNA Biosensor Based on Reduced Graphene Oxide/Water Soluble Quantum Dots for the Detection of Mycobacterium Tuberculosis,” Sens. Actuators, B 241, 1024–1034 (2017).
[Crossref]

Sureshbabu, P.

P. Kanmani, J. Aravind, M. Kamaraj, P. Sureshbabu, and S. Karthikeyan, “Bioresource Technology Environmental Applications of Chitosan and Cellulosic Biopolymers : A Comprehensive Outlook,” Bioresour. Technol. 242, 295–303 (2017).
[Crossref]

Szunerits, S.

L. He, Q. Pagneux, I. Larroulet, A. Y. Serrano, A. Pesquera, A. Zurutuza, D. Mandler, R. Boukherroub, and S. Szunerits, “Label-Free Femtomolar Cancer Biomarker Detection in Human Serum Using Graphene-Coated Surface Plasmon Resonance Chips,” Biosens. Bioelectron. 89, 606–611 (2017).
[Crossref]

Tabasi, O.

O. Tabasi and C. Falamaki, “Analytical Methods Recent Advancements in the Methodologies Applied for the Sensitivity Enhancement of Surface Plasmon Resonance Sensors,” Sens. Actuators, B 10(32), 3906–3925 (2018).

Talib, Z. A.

Y. W. Fen, W. M. M. Yunus, Z. A. Talib, and N. A. Yusof, “Development of Surface Plasmon Resonance Sensor for Determining Zinc Ion Using Novel Active Nanolayers as Probe,” Spectrochim. Acta, Part A 134, 48–52 (2015).
[Crossref]

Y. W. Fen, W. M. M. Yunus, and Z. A. Talib, “Analysis of Pb(II) Ion Sensing by Crosslinked Chitosan Thin Film Using Surface Plasmon Resonance Spectroscopy,” Optik (Stuttg.) 124(2), 126–133 (2013).
[Crossref]

Y. W. Fen, W. M. M. Yunus, and Z. A. Talib, “Real-Time Monitoring of Lead Ion Interaction on Gold/Chitosan Surface Using Surface Plasmon Resonance Spectroscopy,” Indian J. Phys. 86(7), 619–623 (2012).
[Crossref]

Tomar, M.

A. Paliwal, R. Gaur, A. Sharma, M. Tomar, and V. Gupta, “Sensitive Optical Biosensor Based on Surface Plasmon Resonance Using ZnO/Au Bilayered Structure,” Optik (Stuttg.) 127(19), 7642–7647 (2016).
[Crossref]

Tse, W. S.

H. P. Chiang, Y. C. Wang, P. T. Leung, and W. S. Tse, “A Theoretical Model for the Temperature-dependent Sensitivity of the Optical Sensor Based on Surface Plasmon Resonance,” Opt. Commun. 188(5-6), 283–289 (2001).
[Crossref]

Tuntulani, T.

T. Khantaw, C. Boonmee, T. Tuntulani, and W. Ngeontae, “Selective Turn-on Fluorescence Sensor for Ag+ Using Cysteamine Capped CdS Quantum Dots: Determination of Free Ag+ in Silver Nanoparticles Solution,” Talanta 115, 849–856 (2013).
[Crossref]

Tvermoes, B. E.

D. J. Paustenbach, B. E. Tvermoes, K. M. Unice, B. L. Finley, and B. D. Kerger, “A Review of the Health Hazards Posed by Cobalt,” Crit. Rev. Toxicol. 43(4), 316–362 (2013).
[Crossref]

Unice, K. M.

D. J. Paustenbach, B. E. Tvermoes, K. M. Unice, B. L. Finley, and B. D. Kerger, “A Review of the Health Hazards Posed by Cobalt,” Crit. Rev. Toxicol. 43(4), 316–362 (2013).
[Crossref]

Van, K. M.

O. Pluchery, R. Vayron, and K. M. Van, “Laboratory Experiments for Exploring the Surface Plasmon Resonance,” Eur. J. Phys. 32(2), 585–599 (2011).
[Crossref]

Vargas, D. P.

D. P. Vargas, L. Giraldo, and J. C. Moreno-Piraján, “CO2 Adsorption on Activated Carbon Honeycomb-Monoliths: A Comparison of Langmuir and Tóth Models,” Int. J. Mol. Sci. 13(7), 8388–8397 (2012).
[Crossref]

Vayron, R.

O. Pluchery, R. Vayron, and K. M. Van, “Laboratory Experiments for Exploring the Surface Plasmon Resonance,” Eur. J. Phys. 32(2), 585–599 (2011).
[Crossref]

Wan, J.

B. Yu, J. Xu, J. H. Liu, S. T. Yang, J. Luo, Q. Zhou, J. Wan, R. Liao, H. Wang, and Y. Liu, “Adsorption Behavior of Copper Ions on Graphene Oxide-Chitosan Aerogel,” J. Environ. Chem. Eng. 1(4), 1044–1050 (2013).
[Crossref]

Wang, H.

B. Yu, J. Xu, J. H. Liu, S. T. Yang, J. Luo, Q. Zhou, J. Wan, R. Liao, H. Wang, and Y. Liu, “Adsorption Behavior of Copper Ions on Graphene Oxide-Chitosan Aerogel,” J. Environ. Chem. Eng. 1(4), 1044–1050 (2013).
[Crossref]

Wang, Y. C.

H. P. Chiang, Y. C. Wang, P. T. Leung, and W. S. Tse, “A Theoretical Model for the Temperature-dependent Sensitivity of the Optical Sensor Based on Surface Plasmon Resonance,” Opt. Commun. 188(5-6), 283–289 (2001).
[Crossref]

Wasoh, H.

M. H. M. Zaid, J. Abdullah, N. A. Yusof, Y. Sulaiman, H. Wasoh, M. F. M. Noh, and R. Issa, “PNA Biosensor Based on Reduced Graphene Oxide/Water Soluble Quantum Dots for the Detection of Mycobacterium Tuberculosis,” Sens. Actuators, B 241, 1024–1034 (2017).
[Crossref]

Wu, L.

L. Wu, Q. You, Y. Shan, S. Gan, Y. Zhao, and X. Dai, “Few-Layer Ti 3C2Tx MXene : A Promising Surface Plasmon Resonance Biosensing Material to Enhance the Sensitivity,” Sens. Actuators, B 277, 210–215 (2018).
[Crossref]

Wu, S.

X. Huang, Z. Yin, S. Wu, X. Qi, Q. He, Q. Zhang, Q. Yan, F. Boey, and H. Zhang, “Graphene-Based Materials: Synthesis, Characterization, Properties, and Applications,” Small 7(14), 1876–1902 (2011).
[Crossref]

Xu, J.

B. Yu, J. Xu, J. H. Liu, S. T. Yang, J. Luo, Q. Zhou, J. Wan, R. Liao, H. Wang, and Y. Liu, “Adsorption Behavior of Copper Ions on Graphene Oxide-Chitosan Aerogel,” J. Environ. Chem. Eng. 1(4), 1044–1050 (2013).
[Crossref]

Xu, J. X.

D. Kong, F. Y. Yan, J. X. Xu, X. F. Guo, and L. Chen, “Cobalt (II) Ions Detection Using Carbon Dots as an Sensitive and Selective Fluorescent Probe,” RSC Adv. 6(72), 67481–67487 (2016).
[Crossref]

Xu, S. S.

C. H. Zeng, X. T. Meng, S. S. Xu, L. J. Han, S. L. Zhong, and M. Y. Jia, “A Polymorphic Lanthanide Complex as Selective Co2+ Sensor and Luminescent Timer,” Sens. Actuators, B 221, 127–135 (2015).
[Crossref]

Yaacob, M. H.

A. A. Alwahib, A. R. Sadrolhosseini, M. N. An’Amt, H. N. Lim, M. H. Yaacob, M. H. A. Bakar, H. N. Ming, and M. A. Mahdi, “Reduced Graphene Oxide/Maghemite Nanocomposite for Detection of Hydrocarbon Vapor Using Surface Plasmon Resonance,” IEEE Photonics J. 8(4), 1–9 (2016).
[Crossref]

N. H. Kamaruddin, A. A. A. Bakar, M. H. Yaacob, M. A. Mahdi, M. S. D. Zan, and S. Shaari, “Enhancement of Chitosan-Graphene Oxide SPR Sensor with a Multi-Metallic Layers of Au-Ag-Au Nanostructure for Lead(II) Ion Detection,” Appl. Surf. Sci. 361, 177–184 (2016).
[Crossref]

N. F. Lokman, A. A. A. Bakar, H. F. S. Abdullah, W. B. W. A. Rahman, N. M. Huang, and M. H. Yaacob, “Highly Sensitive SPR Response of Au/Chitosan/Graphene Oxide Nanostructured Thin Films toward Pb(II) Ions,” Sens. Actuators, B 195, 459–466 (2014).
[Crossref]

Yan, F. Y.

D. Kong, F. Y. Yan, J. X. Xu, X. F. Guo, and L. Chen, “Cobalt (II) Ions Detection Using Carbon Dots as an Sensitive and Selective Fluorescent Probe,” RSC Adv. 6(72), 67481–67487 (2016).
[Crossref]

Yan, Q.

X. Huang, Z. Yin, S. Wu, X. Qi, Q. He, Q. Zhang, Q. Yan, F. Boey, and H. Zhang, “Graphene-Based Materials: Synthesis, Characterization, Properties, and Applications,” Small 7(14), 1876–1902 (2011).
[Crossref]

Yang, S. T.

B. Yu, J. Xu, J. H. Liu, S. T. Yang, J. Luo, Q. Zhou, J. Wan, R. Liao, H. Wang, and Y. Liu, “Adsorption Behavior of Copper Ions on Graphene Oxide-Chitosan Aerogel,” J. Environ. Chem. Eng. 1(4), 1044–1050 (2013).
[Crossref]

Yasmeen, S.

S. Yasmeen, M. Kabiraz, B. Saha, M. Qadir, M. Gafur, and S. Masum, “Chromium (VI) Ions Removal from Tannery Effluent Using Chitosan-Microcrystalline Cellulose Composite as Adsorbent,” Int. Res. J. Pure Appl. Chem. 10(4), 1–14 (2016).
[Crossref]

Ye, B. C.

M. Zhang, Y. Q. Liu, and B. C. Ye, “Colorimetric Assay for Parallel Detection of Cd2+, Ni2+ and Co2+ Using Peptide-Modified Gold Nanoparticles,” Analyst 137(3), 601–607 (2012).
[Crossref]

Yin, Z.

X. Huang, Z. Yin, S. Wu, X. Qi, Q. He, Q. Zhang, Q. Yan, F. Boey, and H. Zhang, “Graphene-Based Materials: Synthesis, Characterization, Properties, and Applications,” Small 7(14), 1876–1902 (2011).
[Crossref]

Yoon, P. W.

H. I. Choi, J. A. Hong, M. S. Kim, S. E. Lee, S. H. Jung, P. W. Yoon, J. S. Song, and J. J. Kim, “Severe Cardiomyopathy Due to Arthroprosthetic Cobaltism: Report of Two Cases with Different Outcomes,” Cardiovasc. Toxicol. 19(1), 82–89 (2019).
[Crossref]

You, Q.

L. Wu, Q. You, Y. Shan, S. Gan, Y. Zhao, and X. Dai, “Few-Layer Ti 3C2Tx MXene : A Promising Surface Plasmon Resonance Biosensing Material to Enhance the Sensitivity,” Sens. Actuators, B 277, 210–215 (2018).
[Crossref]

Yu, B.

B. Yu, J. Xu, J. H. Liu, S. T. Yang, J. Luo, Q. Zhou, J. Wan, R. Liao, H. Wang, and Y. Liu, “Adsorption Behavior of Copper Ions on Graphene Oxide-Chitosan Aerogel,” J. Environ. Chem. Eng. 1(4), 1044–1050 (2013).
[Crossref]

Yu, Q.

X. Zhou, K. Chen, L. Li, W. Peng, and Q. Yu, “Angle Modulated Surface Plasmon Resonance Spectrometer for Refractive Index Sensing with Enhanced Detection Resolution,” Opt. Commun. 382, 610–614 (2017).
[Crossref]

Yunus, W. M. M.

Y. W. Fen, W. M. M. Yunus, Z. A. Talib, and N. A. Yusof, “Development of Surface Plasmon Resonance Sensor for Determining Zinc Ion Using Novel Active Nanolayers as Probe,” Spectrochim. Acta, Part A 134, 48–52 (2015).
[Crossref]

Y. W. Fen, W. M. M. Yunus, N. A. Yusof, N. S. Ishak, N. A. S. Omar, and A. A. Zainudin, “Preparation, Characterization and Optical Properties of Ionophore Doped Chitosan Biopolymer Thin Film and Its Potential Application for Sensing Metal Ion,” Optik (Stuttg.) 126(23), 4688–4692 (2015).
[Crossref]

Y. W. Fen and W. M. M. Yunus, “Utilization of Chitosan-Based Sensor Thin Films for the Detection of Lead Ion by Surface Plasmon Resonance Optical Sensor,” IEEE Sens. J. 13(5), 1413–1418 (2013).
[Crossref]

Y. W. Fen and W. M. M. Yunus, “Surface Plasmon Resonance Spectroscopy as an Alternative for Sensing Heavy Metal Ions: A Review,” Sens. Rev. 33(4), 305–314 (2013).
[Crossref]

Y. W. Fen, W. M. M. Yunus, and Z. A. Talib, “Analysis of Pb(II) Ion Sensing by Crosslinked Chitosan Thin Film Using Surface Plasmon Resonance Spectroscopy,” Optik (Stuttg.) 124(2), 126–133 (2013).
[Crossref]

Y. W. Fen, W. M. M. Yunus, and N. A. Yusof, “Surface Plasmon Resonance Optical Sensor for Detection of Pb2+ Based on Immobilized P-Tert-Butylcalix[4]Arene-Tetrakis in Chitosan Thin Film as an Active Layer,” Sens. Actuators, B 171-172, 287–293 (2012).
[Crossref]

Y. W. Fen, W. M. M. Yunus, and Z. A. Talib, “Real-Time Monitoring of Lead Ion Interaction on Gold/Chitosan Surface Using Surface Plasmon Resonance Spectroscopy,” Indian J. Phys. 86(7), 619–623 (2012).
[Crossref]

Y. W. Fen and W. M. M. Yunus, “Characterization of the Optical Properties of Heavy Metal Ions Using Surface Plasmon Resonance Technique,” Opt. Photonics J. 01(03), 116–123 (2011).
[Crossref]

Y. W. Fen, W. M. M. Yunus, and N. A. Yusof, “Optical Properties of Cross-Linked Chitosan Thin Film for Copper Ion Detection Using Surface Plasmon Resonance Technique,” Opt. Appl. 41(4), 999–1013 (2011).

Yusof, N. A.

A. A. Zainudin, Y. W. Fen, N. A. Yusof, S. H. Al-Rekabi, M. A. Mahdi, and N. A. S. Omar, “Incorporation of Surface Plasmon Resonance with Novel Valinomycin Doped Chitosan-Graphene Oxide Thin Film for Sensing Potassium Ion. Spectrochim,” Spectrochim. Acta, Part A 191, 111–115 (2018).
[Crossref]

A. A. Zainudin, Y. W. Fen, N. A. Yusof, and N. A. S. Omar, “Structural, Optical and Sensing Properties of Ionophore Doped Graphene Based Bionanocomposite Thin Film,” Optik (Stuttg.) 144, 308–315 (2017).
[Crossref]

S. Saleviter, Y. W. Fen, N. A. S. Omar, A. A. Zainudin, and N. A. Yusof, “Development of Optical Sensor for Determination of Co(II) Based on Surface Plasmon Resonance Phenomenon,” Sens. Lett. 15(10), 862–867 (2017).
[Crossref]

M. H. M. Zaid, J. Abdullah, N. A. Yusof, Y. Sulaiman, H. Wasoh, M. F. M. Noh, and R. Issa, “PNA Biosensor Based on Reduced Graphene Oxide/Water Soluble Quantum Dots for the Detection of Mycobacterium Tuberculosis,” Sens. Actuators, B 241, 1024–1034 (2017).
[Crossref]

Y. W. Fen, W. M. M. Yunus, N. A. Yusof, N. S. Ishak, N. A. S. Omar, and A. A. Zainudin, “Preparation, Characterization and Optical Properties of Ionophore Doped Chitosan Biopolymer Thin Film and Its Potential Application for Sensing Metal Ion,” Optik (Stuttg.) 126(23), 4688–4692 (2015).
[Crossref]

Y. W. Fen, W. M. M. Yunus, Z. A. Talib, and N. A. Yusof, “Development of Surface Plasmon Resonance Sensor for Determining Zinc Ion Using Novel Active Nanolayers as Probe,” Spectrochim. Acta, Part A 134, 48–52 (2015).
[Crossref]

Y. W. Fen, W. M. M. Yunus, and N. A. Yusof, “Surface Plasmon Resonance Optical Sensor for Detection of Pb2+ Based on Immobilized P-Tert-Butylcalix[4]Arene-Tetrakis in Chitosan Thin Film as an Active Layer,” Sens. Actuators, B 171-172, 287–293 (2012).
[Crossref]

Y. W. Fen, W. M. M. Yunus, and N. A. Yusof, “Optical Properties of Cross-Linked Chitosan Thin Film for Copper Ion Detection Using Surface Plasmon Resonance Technique,” Opt. Appl. 41(4), 999–1013 (2011).

N. A. Yusof and M. Ahmad, “A Flow Cell Optosensor for Determination of Co(II) Based on Immobilised 2-(4-Pyridylazo)Resorcinol in Chitosan Membrane by Using Stopped Flow, Flow Injection Analysis,” Sens. Actuators, B 86(2-3), 127–133 (2002).
[Crossref]

Zaid, M. H. M.

N. A. S. Omar, Y. W. Fen, J. Abdullah, M. H. M. Zaid, and M. A. Mahdi, “Structural, Optical and Sensing Properties of CdS-NH2GO Thin Film as a Dengue Virus E-protein Sensing Material,” Optik (Stuttg.) 171, 934–940 (2018).
[Crossref]

M. H. M. Zaid, J. Abdullah, N. A. Yusof, Y. Sulaiman, H. Wasoh, M. F. M. Noh, and R. Issa, “PNA Biosensor Based on Reduced Graphene Oxide/Water Soluble Quantum Dots for the Detection of Mycobacterium Tuberculosis,” Sens. Actuators, B 241, 1024–1034 (2017).
[Crossref]

Zainudin, A. A.

A. A. Zainudin, Y. W. Fen, N. A. Yusof, S. H. Al-Rekabi, M. A. Mahdi, and N. A. S. Omar, “Incorporation of Surface Plasmon Resonance with Novel Valinomycin Doped Chitosan-Graphene Oxide Thin Film for Sensing Potassium Ion. Spectrochim,” Spectrochim. Acta, Part A 191, 111–115 (2018).
[Crossref]

A. A. Zainudin, Y. W. Fen, N. A. Yusof, and N. A. S. Omar, “Structural, Optical and Sensing Properties of Ionophore Doped Graphene Based Bionanocomposite Thin Film,” Optik (Stuttg.) 144, 308–315 (2017).
[Crossref]

S. Saleviter, Y. W. Fen, N. A. S. Omar, A. A. Zainudin, and N. A. Yusof, “Development of Optical Sensor for Determination of Co(II) Based on Surface Plasmon Resonance Phenomenon,” Sens. Lett. 15(10), 862–867 (2017).
[Crossref]

Y. W. Fen, W. M. M. Yunus, N. A. Yusof, N. S. Ishak, N. A. S. Omar, and A. A. Zainudin, “Preparation, Characterization and Optical Properties of Ionophore Doped Chitosan Biopolymer Thin Film and Its Potential Application for Sensing Metal Ion,” Optik (Stuttg.) 126(23), 4688–4692 (2015).
[Crossref]

Zan, M. S.

N. Kamaruddin, A. A. Bakar, N. Mobarak, M. S. Zan, and N. Arsad, “Binding Affinity of a Highly Sensitive Au/Ag/Au/Chitosan-Graphene Oxide Sensor Based on Direct Detection of Pb2+ and Hg2+ Ions,” Sensors 17(10), 2277 (2017).
[Crossref]

Zan, M. S. D.

N. H. Kamaruddin, A. A. A. Bakar, M. H. Yaacob, M. A. Mahdi, M. S. D. Zan, and S. Shaari, “Enhancement of Chitosan-Graphene Oxide SPR Sensor with a Multi-Metallic Layers of Au-Ag-Au Nanostructure for Lead(II) Ion Detection,” Appl. Surf. Sci. 361, 177–184 (2016).
[Crossref]

Zeng, C. H.

C. H. Zeng, X. T. Meng, S. S. Xu, L. J. Han, S. L. Zhong, and M. Y. Jia, “A Polymorphic Lanthanide Complex as Selective Co2+ Sensor and Luminescent Timer,” Sens. Actuators, B 221, 127–135 (2015).
[Crossref]

Zeng, J.

X. Luo, J. Zeng, S. Liu, and L. Zhang, “Bioresource Technology an Effective and Recyclable Adsorbent for the Removal of Heavy Metal Ions from Aqueous System : Magnetic Chitosan/Cellulose Microspheres,” Bioresour. Technol. 194, 403–406 (2015).
[Crossref]

Zeng, S.

K. Li, W. Zhou, and S. Zeng, “Optical Micro/Nanofiber-Based Localized Surface Plasmon Resonance Biosensors: Fiber Diameter Dependence,” Sensors 18(10), 3295 (2018).
[Crossref]

Zhang, H.

X. Huang, Z. Yin, S. Wu, X. Qi, Q. He, Q. Zhang, Q. Yan, F. Boey, and H. Zhang, “Graphene-Based Materials: Synthesis, Characterization, Properties, and Applications,” Small 7(14), 1876–1902 (2011).
[Crossref]

Zhang, L.

X. Luo, J. Zeng, S. Liu, and L. Zhang, “Bioresource Technology an Effective and Recyclable Adsorbent for the Removal of Heavy Metal Ions from Aqueous System : Magnetic Chitosan/Cellulose Microspheres,” Bioresour. Technol. 194, 403–406 (2015).
[Crossref]

Zhang, M.

M. Zhang, Y. Q. Liu, and B. C. Ye, “Colorimetric Assay for Parallel Detection of Cd2+, Ni2+ and Co2+ Using Peptide-Modified Gold Nanoparticles,” Analyst 137(3), 601–607 (2012).
[Crossref]

Zhang, Q.

X. Huang, Z. Yin, S. Wu, X. Qi, Q. He, Q. Zhang, Q. Yan, F. Boey, and H. Zhang, “Graphene-Based Materials: Synthesis, Characterization, Properties, and Applications,” Small 7(14), 1876–1902 (2011).
[Crossref]

Zhao, Y.

L. Wu, Q. You, Y. Shan, S. Gan, Y. Zhao, and X. Dai, “Few-Layer Ti 3C2Tx MXene : A Promising Surface Plasmon Resonance Biosensing Material to Enhance the Sensitivity,” Sens. Actuators, B 277, 210–215 (2018).
[Crossref]

Zhong, S. L.

C. H. Zeng, X. T. Meng, S. S. Xu, L. J. Han, S. L. Zhong, and M. Y. Jia, “A Polymorphic Lanthanide Complex as Selective Co2+ Sensor and Luminescent Timer,” Sens. Actuators, B 221, 127–135 (2015).
[Crossref]

Zhou, Q.

B. Yu, J. Xu, J. H. Liu, S. T. Yang, J. Luo, Q. Zhou, J. Wan, R. Liao, H. Wang, and Y. Liu, “Adsorption Behavior of Copper Ions on Graphene Oxide-Chitosan Aerogel,” J. Environ. Chem. Eng. 1(4), 1044–1050 (2013).
[Crossref]

Zhou, W.

K. Li, W. Zhou, and S. Zeng, “Optical Micro/Nanofiber-Based Localized Surface Plasmon Resonance Biosensors: Fiber Diameter Dependence,” Sensors 18(10), 3295 (2018).
[Crossref]

Zhou, X.

X. Zhou, K. Chen, L. Li, W. Peng, and Q. Yu, “Angle Modulated Surface Plasmon Resonance Spectrometer for Refractive Index Sensing with Enhanced Detection Resolution,” Opt. Commun. 382, 610–614 (2017).
[Crossref]

Zulholinda, M.

M. D. A. Roshidi, Y. W. Fen, W. M. E. M. M. Daniyal, N. A. S. Omar, and M. Zulholinda, “Structural and Optical Properties of Chitosan–Poly (amidoamine) Dendrimer Composite Thin Film for Potential Sensing Pb2+ using an Optical Spectroscopy,” Optik (Stuttg.) 185, 351–358 (2019).
[Crossref]

Zurutuza, A.

L. He, Q. Pagneux, I. Larroulet, A. Y. Serrano, A. Pesquera, A. Zurutuza, D. Mandler, R. Boukherroub, and S. Szunerits, “Label-Free Femtomolar Cancer Biomarker Detection in Human Serum Using Graphene-Coated Surface Plasmon Resonance Chips,” Biosens. Bioelectron. 89, 606–611 (2017).
[Crossref]

ACS Sustainable Chem. Eng. (1)

H. Sharma, A. Singh, N. Kaur, and N. Singh, “ZnO-Based Imine-Linked Coupled Biocompatible Chemosensor for Nanomolar Detection of Co2+,” ACS Sustainable Chem. Eng. 1(12), 1600–1608 (2013).
[Crossref]

Anal. Methods (1)

V. N. Mehta, A. K. Mungara, and S. K. Kailasa, “Dopamine Dithiocarbamate Functionalized Silver Nanoparticles as Colorimetric Sensors for the Detection of Cobalt Ion,” Anal. Methods 5(7), 1818–1822 (2013).
[Crossref]

Analyst (1)

M. Zhang, Y. Q. Liu, and B. C. Ye, “Colorimetric Assay for Parallel Detection of Cd2+, Ni2+ and Co2+ Using Peptide-Modified Gold Nanoparticles,” Analyst 137(3), 601–607 (2012).
[Crossref]

Appl. Surf. Sci. (1)

N. H. Kamaruddin, A. A. A. Bakar, M. H. Yaacob, M. A. Mahdi, M. S. D. Zan, and S. Shaari, “Enhancement of Chitosan-Graphene Oxide SPR Sensor with a Multi-Metallic Layers of Au-Ag-Au Nanostructure for Lead(II) Ion Detection,” Appl. Surf. Sci. 361, 177–184 (2016).
[Crossref]

Bioresour. Technol. (2)

P. Kanmani, J. Aravind, M. Kamaraj, P. Sureshbabu, and S. Karthikeyan, “Bioresource Technology Environmental Applications of Chitosan and Cellulosic Biopolymers : A Comprehensive Outlook,” Bioresour. Technol. 242, 295–303 (2017).
[Crossref]

X. Luo, J. Zeng, S. Liu, and L. Zhang, “Bioresource Technology an Effective and Recyclable Adsorbent for the Removal of Heavy Metal Ions from Aqueous System : Magnetic Chitosan/Cellulose Microspheres,” Bioresour. Technol. 194, 403–406 (2015).
[Crossref]

Biosens. Bioelectron. (2)

S. Liu, W. Na, S. Pang, and X. Su, “Fluorescence Detection of Pb2+based on the DNA Sequence Functionalized CdS Quantum Dots,” Biosens. Bioelectron. 58, 17–21 (2014).
[Crossref]

L. He, Q. Pagneux, I. Larroulet, A. Y. Serrano, A. Pesquera, A. Zurutuza, D. Mandler, R. Boukherroub, and S. Szunerits, “Label-Free Femtomolar Cancer Biomarker Detection in Human Serum Using Graphene-Coated Surface Plasmon Resonance Chips,” Biosens. Bioelectron. 89, 606–611 (2017).
[Crossref]

Cardiovasc. Toxicol. (1)

H. I. Choi, J. A. Hong, M. S. Kim, S. E. Lee, S. H. Jung, P. W. Yoon, J. S. Song, and J. J. Kim, “Severe Cardiomyopathy Due to Arthroprosthetic Cobaltism: Report of Two Cases with Different Outcomes,” Cardiovasc. Toxicol. 19(1), 82–89 (2019).
[Crossref]

Chem. Eng. J. (1)

U. Jeong, H. H. Shin, and Y. H. Kim, “Functionalized Magnetic Core-shell Fe@SiO2 Nanoparticles as Recoverable Colorimetric Sensor for Co2+ Ion,” Chem. Eng. J. 281, 428–433 (2015).
[Crossref]

Crit. Rev. Toxicol. (1)

D. J. Paustenbach, B. E. Tvermoes, K. M. Unice, B. L. Finley, and B. D. Kerger, “A Review of the Health Hazards Posed by Cobalt,” Crit. Rev. Toxicol. 43(4), 316–362 (2013).
[Crossref]

Eur. J. Phys. (1)

O. Pluchery, R. Vayron, and K. M. Van, “Laboratory Experiments for Exploring the Surface Plasmon Resonance,” Eur. J. Phys. 32(2), 585–599 (2011).
[Crossref]

Groundw. Sustain. Dev. (1)

S. B. D. Borah, T. Bora, S. Baruah, and J. Dutta, “Heavy Metal Ion Sensing in Water Using Surface Plasmon Resonance of Metallic Nanostructures,” Groundw. Sustain. Dev. 1(1-2), 1–11 (2015).
[Crossref]

IEEE Photonics J. (1)

A. A. Alwahib, A. R. Sadrolhosseini, M. N. An’Amt, H. N. Lim, M. H. Yaacob, M. H. A. Bakar, H. N. Ming, and M. A. Mahdi, “Reduced Graphene Oxide/Maghemite Nanocomposite for Detection of Hydrocarbon Vapor Using Surface Plasmon Resonance,” IEEE Photonics J. 8(4), 1–9 (2016).
[Crossref]

IEEE Sens. J. (2)

Y. W. Fen and W. M. M. Yunus, “Utilization of Chitosan-Based Sensor Thin Films for the Detection of Lead Ion by Surface Plasmon Resonance Optical Sensor,” IEEE Sens. J. 13(5), 1413–1418 (2013).
[Crossref]

A. Sharma, R. Jha, and B. Gupta, “Fiber-Optic Sensors Based on Surface Plasmon Resonance: A Comprehensive Review,” IEEE Sens. J. 7(8), 1118–1129 (2007).
[Crossref]

Indian J. Phys. (1)

Y. W. Fen, W. M. M. Yunus, and Z. A. Talib, “Real-Time Monitoring of Lead Ion Interaction on Gold/Chitosan Surface Using Surface Plasmon Resonance Spectroscopy,” Indian J. Phys. 86(7), 619–623 (2012).
[Crossref]

Int. J. Mol. Sci. (1)

D. P. Vargas, L. Giraldo, and J. C. Moreno-Piraján, “CO2 Adsorption on Activated Carbon Honeycomb-Monoliths: A Comparison of Langmuir and Tóth Models,” Int. J. Mol. Sci. 13(7), 8388–8397 (2012).
[Crossref]

Int. Res. J. Pure Appl. Chem. (1)

S. Yasmeen, M. Kabiraz, B. Saha, M. Qadir, M. Gafur, and S. Masum, “Chromium (VI) Ions Removal from Tannery Effluent Using Chitosan-Microcrystalline Cellulose Composite as Adsorbent,” Int. Res. J. Pure Appl. Chem. 10(4), 1–14 (2016).
[Crossref]

J. Chem. Heal. Risks (1)

J. Abolhasani, “Fluorescence Quenching of CdS Quantum Dots and Its Application to Determination of Copper and Nickel Contamination in Well and Dam Water,” J. Chem. Heal. Risks 5(2), 145–154 (2015).

J. Contam. Hydrol. (1)

G. P. Jeppu and T. P. A. Clement, “Modified Langmuir-Freundlich Isotherm Model for Simulating PH-Dependent Adsorption Effects,” J. Contam. Hydrol. 129-130, 46–53 (2012).
[Crossref]

J. Environ. Chem. Eng. (1)

B. Yu, J. Xu, J. H. Liu, S. T. Yang, J. Luo, Q. Zhou, J. Wan, R. Liao, H. Wang, and Y. Liu, “Adsorption Behavior of Copper Ions on Graphene Oxide-Chitosan Aerogel,” J. Environ. Chem. Eng. 1(4), 1044–1050 (2013).
[Crossref]

J. Mol. Liq. (1)

A. Sionkowska and A. Płanecka, “Surface Properties of Thin Films Based on the Mixtures of Chitosan and Silk Fibroin,” J. Mol. Liq. 186, 157–162 (2013).
[Crossref]

J. Nanomater. (1)

S. Saleviter, Y. W. Fen, N. A. S. Omar, W. M. E. M. Daniyal, and J. Abdullah, “Structural and Optical Studies of Cadmium Sulfide Quantum Dot-Graphene Oxide-Chitosan Nanocomposite Thin Film as a Novel SPR Spectroscopy Active Layer,” J. Nanomater. 2018, 1–8 (2018).
[Crossref]

Opt. Appl. (1)

Y. W. Fen, W. M. M. Yunus, and N. A. Yusof, “Optical Properties of Cross-Linked Chitosan Thin Film for Copper Ion Detection Using Surface Plasmon Resonance Technique,” Opt. Appl. 41(4), 999–1013 (2011).

Opt. Commun. (3)

X. Zhou, K. Chen, L. Li, W. Peng, and Q. Yu, “Angle Modulated Surface Plasmon Resonance Spectrometer for Refractive Index Sensing with Enhanced Detection Resolution,” Opt. Commun. 382, 610–614 (2017).
[Crossref]

H. P. Chiang, Y. C. Wang, P. T. Leung, and W. S. Tse, “A Theoretical Model for the Temperature-dependent Sensitivity of the Optical Sensor Based on Surface Plasmon Resonance,” Opt. Commun. 188(5-6), 283–289 (2001).
[Crossref]

A. R. Sadrolhosseini, M. Naseri, and H. M. Kamari, “Surface Plasmon Resonance Sensor for Detecting of Arsenic in Aqueous Solution Using Polypyrrole-Chitosan-Cobalt Ferrite Nanoparticles Composite Layer,” Opt. Commun. 383, 132–137 (2017).
[Crossref]

Opt. Express (1)

Opt. Photonics J. (1)

Y. W. Fen and W. M. M. Yunus, “Characterization of the Optical Properties of Heavy Metal Ions Using Surface Plasmon Resonance Technique,” Opt. Photonics J. 01(03), 116–123 (2011).
[Crossref]

Optik (Stuttg.) (7)

Y. W. Fen, W. M. M. Yunus, N. A. Yusof, N. S. Ishak, N. A. S. Omar, and A. A. Zainudin, “Preparation, Characterization and Optical Properties of Ionophore Doped Chitosan Biopolymer Thin Film and Its Potential Application for Sensing Metal Ion,” Optik (Stuttg.) 126(23), 4688–4692 (2015).
[Crossref]

M. D. A. Roshidi, Y. W. Fen, W. M. E. M. M. Daniyal, N. A. S. Omar, and M. Zulholinda, “Structural and Optical Properties of Chitosan–Poly (amidoamine) Dendrimer Composite Thin Film for Potential Sensing Pb2+ using an Optical Spectroscopy,” Optik (Stuttg.) 185, 351–358 (2019).
[Crossref]

A. Paliwal, R. Gaur, A. Sharma, M. Tomar, and V. Gupta, “Sensitive Optical Biosensor Based on Surface Plasmon Resonance Using ZnO/Au Bilayered Structure,” Optik (Stuttg.) 127(19), 7642–7647 (2016).
[Crossref]

A. A. Zainudin, Y. W. Fen, N. A. Yusof, and N. A. S. Omar, “Structural, Optical and Sensing Properties of Ionophore Doped Graphene Based Bionanocomposite Thin Film,” Optik (Stuttg.) 144, 308–315 (2017).
[Crossref]

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, S. Saleviter, and N. A. Sheh Omar, “Preparation and Characterization of Hexadecyltrimethylammonium Bromide Modified Nanocrystalline Cellulose/Graphene Oxide Composite Thin Film and Its Potential in Sensing Copper Ion Using Surface Plasmon Resonance Technique,” Optik (Stuttg.) 173, 71–77 (2018).
[Crossref]

Y. W. Fen, W. M. M. Yunus, and Z. A. Talib, “Analysis of Pb(II) Ion Sensing by Crosslinked Chitosan Thin Film Using Surface Plasmon Resonance Spectroscopy,” Optik (Stuttg.) 124(2), 126–133 (2013).
[Crossref]

N. A. S. Omar, Y. W. Fen, J. Abdullah, M. H. M. Zaid, and M. A. Mahdi, “Structural, Optical and Sensing Properties of CdS-NH2GO Thin Film as a Dengue Virus E-protein Sensing Material,” Optik (Stuttg.) 171, 934–940 (2018).
[Crossref]

Pet. Coal. (1)

M. Asgari, H. Anisi, H. Mohammadi, and S. Sadighi, “Designing a Commercial Scale Pressure Swing Adsorber for Hydrogen Purification,” Pet. Coal. 56(5), 552–561 (2014).

Polish J. Environ. Stud. (1)

D. Barałkiewicz and J. Siepak, “Chromium, Nickel and Cobalt in Environmental Samples and Existing Legal Norms,” Polish J. Environ. Stud. 8(4), 201–208 (1999).

React. Funct. Polym. (1)

M. N. R. Kumar, “A Review of Chitin and Chitosan Applications. Reactive and Functional Polymers,” React. Funct. Polym. 46(1), 1–27 (2000).
[Crossref]

Res. Chem. Intermed. (1)

U. B. Patel, V. N. Mehta, A. K. Mungara, and S. K. Kailasa, “4-Aminothiophenol Functionalized Gold Nanoparticles as Colorimetric Sensors for the Detection of Cobalt Using UV–Visible Spectrometry,” Res. Chem. Intermed. 39(2), 771–779 (2013).
[Crossref]

RSC Adv. (1)

D. Kong, F. Y. Yan, J. X. Xu, X. F. Guo, and L. Chen, “Cobalt (II) Ions Detection Using Carbon Dots as an Sensitive and Selective Fluorescent Probe,” RSC Adv. 6(72), 67481–67487 (2016).
[Crossref]

Sci. Total Environ. (1)

R. Lauwerys and D. Lison, “Health Risks Associated with Cobalt Exposure An Overview,” Sci. Total Environ. 150(1-3), 1–6 (1994).
[Crossref]

Science (1)

F. T. Manheim, “Marine cobalt resources,” Science 232(4750), 600–608 (1986).
[Crossref]

Sens. Actuators, B (8)

O. Tabasi and C. Falamaki, “Analytical Methods Recent Advancements in the Methodologies Applied for the Sensitivity Enhancement of Surface Plasmon Resonance Sensors,” Sens. Actuators, B 10(32), 3906–3925 (2018).

L. Wu, Q. You, Y. Shan, S. Gan, Y. Zhao, and X. Dai, “Few-Layer Ti 3C2Tx MXene : A Promising Surface Plasmon Resonance Biosensing Material to Enhance the Sensitivity,” Sens. Actuators, B 277, 210–215 (2018).
[Crossref]

Y. W. Fen, W. M. M. Yunus, and N. A. Yusof, “Surface Plasmon Resonance Optical Sensor for Detection of Pb2+ Based on Immobilized P-Tert-Butylcalix[4]Arene-Tetrakis in Chitosan Thin Film as an Active Layer,” Sens. Actuators, B 171-172, 287–293 (2012).
[Crossref]

P. Singh, “SPR Biosensors: Historical Perspectives and Current Challenges,” Sens. Actuators, B 229, 110–130 (2016).
[Crossref]

N. A. Yusof and M. Ahmad, “A Flow Cell Optosensor for Determination of Co(II) Based on Immobilised 2-(4-Pyridylazo)Resorcinol in Chitosan Membrane by Using Stopped Flow, Flow Injection Analysis,” Sens. Actuators, B 86(2-3), 127–133 (2002).
[Crossref]

C. H. Zeng, X. T. Meng, S. S. Xu, L. J. Han, S. L. Zhong, and M. Y. Jia, “A Polymorphic Lanthanide Complex as Selective Co2+ Sensor and Luminescent Timer,” Sens. Actuators, B 221, 127–135 (2015).
[Crossref]

M. H. M. Zaid, J. Abdullah, N. A. Yusof, Y. Sulaiman, H. Wasoh, M. F. M. Noh, and R. Issa, “PNA Biosensor Based on Reduced Graphene Oxide/Water Soluble Quantum Dots for the Detection of Mycobacterium Tuberculosis,” Sens. Actuators, B 241, 1024–1034 (2017).
[Crossref]

N. F. Lokman, A. A. A. Bakar, H. F. S. Abdullah, W. B. W. A. Rahman, N. M. Huang, and M. H. Yaacob, “Highly Sensitive SPR Response of Au/Chitosan/Graphene Oxide Nanostructured Thin Films toward Pb(II) Ions,” Sens. Actuators, B 195, 459–466 (2014).
[Crossref]

Sens. Lett. (1)

S. Saleviter, Y. W. Fen, N. A. S. Omar, A. A. Zainudin, and N. A. Yusof, “Development of Optical Sensor for Determination of Co(II) Based on Surface Plasmon Resonance Phenomenon,” Sens. Lett. 15(10), 862–867 (2017).
[Crossref]

Sens. Rev. (2)

N. A. S. Omar and Y. W. Fen, “Recent Development of SPR Spectroscopy as Potential Method for Diagnosis of Dengue Virus E-Protein,” Sens. Rev. 38(1), 106–116 (2018).
[Crossref]

Y. W. Fen and W. M. M. Yunus, “Surface Plasmon Resonance Spectroscopy as an Alternative for Sensing Heavy Metal Ions: A Review,” Sens. Rev. 33(4), 305–314 (2013).
[Crossref]

Sensors (2)

K. Li, W. Zhou, and S. Zeng, “Optical Micro/Nanofiber-Based Localized Surface Plasmon Resonance Biosensors: Fiber Diameter Dependence,” Sensors 18(10), 3295 (2018).
[Crossref]

N. Kamaruddin, A. A. Bakar, N. Mobarak, M. S. Zan, and N. Arsad, “Binding Affinity of a Highly Sensitive Au/Ag/Au/Chitosan-Graphene Oxide Sensor Based on Direct Detection of Pb2+ and Hg2+ Ions,” Sensors 17(10), 2277 (2017).
[Crossref]

Small (1)

X. Huang, Z. Yin, S. Wu, X. Qi, Q. He, Q. Zhang, Q. Yan, F. Boey, and H. Zhang, “Graphene-Based Materials: Synthesis, Characterization, Properties, and Applications,” Small 7(14), 1876–1902 (2011).
[Crossref]

Spectrochim. Acta, Part A (3)

Y. W. Fen, W. M. M. Yunus, Z. A. Talib, and N. A. Yusof, “Development of Surface Plasmon Resonance Sensor for Determining Zinc Ion Using Novel Active Nanolayers as Probe,” Spectrochim. Acta, Part A 134, 48–52 (2015).
[Crossref]

W. M. E. M. M. Daniyal, Y. W. Fen, J. Abdullah, A. R. Sadrolhosseini, S. Saleviter, and N. A. S. Omar, “Label-free optical spectroscopy for characterizing binding properties of highly sensitive nanocrystalline cellulose-graphene oxide based nanocomposite towards nickel ion,” Spectrochim. Acta, Part A 212, 25–31 (2019).
[Crossref]

A. A. Zainudin, Y. W. Fen, N. A. Yusof, S. H. Al-Rekabi, M. A. Mahdi, and N. A. S. Omar, “Incorporation of Surface Plasmon Resonance with Novel Valinomycin Doped Chitosan-Graphene Oxide Thin Film for Sensing Potassium Ion. Spectrochim,” Spectrochim. Acta, Part A 191, 111–115 (2018).
[Crossref]

Talanta (1)

T. Khantaw, C. Boonmee, T. Tuntulani, and W. Ngeontae, “Selective Turn-on Fluorescence Sensor for Ag+ Using Cysteamine Capped CdS Quantum Dots: Determination of Free Ag+ in Silver Nanoparticles Solution,” Talanta 115, 849–856 (2013).
[Crossref]

Waste Manage. (1)

C. Lupi, M. Pasquali, and A. Dell’Era, “Nickel and Cobalt Recycling from Lithium-Ion Batteries by Electrochemical Processes,” Waste Manage. 25(2), 215–220 (2005).
[Crossref]

Water, Air, Soil Pollut. (2)

Y. S. Ho, J. F. Porter, and G. McKay, “Equilibrium Isotherm Studies for the Sorption of Divalent Metal Ions onto Peat: Copper, Nickel and Lead Single Component Systems,” Water, Air, Soil Pollut. 141(1/4), 1–33 (2002).
[Crossref]

N. A. S. Omar, Y. W. Fen, J. Abdullah, C. E. N. C. E. Chik, and M. A. Mahdi, “Development of an Optical Sensor Based on Surface Plasmon Resonance Phenomenon for Diagnosis of Dengue Virus E-Protein,” Water, Air, Soil Pollut. 20, 16–21 (2018).
[Crossref]

Cited By

OSA participates in Crossref's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (10)

Fig. 1.
Fig. 1. Schematic diagram of surface plasmon resonance spectroscopy.
Fig. 2.
Fig. 2. SPR curve of gold film in contact with deionized water.
Fig. 3.
Fig. 3. SPR curves of gold film in contact with different concentration of Co2+ (0 to 100 ppm).
Fig. 4.
Fig. 4. SPR curve of gold/chitosan-GO/CdS QDs active layer in contact with deionized water.
Fig. 5.
Fig. 5. SPR curves of gold/chitosan-GO/CdS QDs active layer in contact with different concentration of Co2+ (0 to 100 ppm).
Fig. 6.
Fig. 6. SPR angle shift against Co2+ concentration.
Fig. 7.
Fig. 7. The FWHM of SPR curve corresponding to half from its maximum value.
Fig. 8.
Fig. 8. Detection accuracy of the chitosan-GO/CdS QDs based SPR sensor towards Co2+.
Fig. 9.
Fig. 9. Signal-to-noise ratio of the chitosan-GO/CdS QDs based SPR sensor towards Co2+.
Fig. 10.
Fig. 10. Equilibrium isotherm models fitting for the resonance angle shift of Co2+ in contact with gold/chitosan-GO/CdS Qds active layer and gold thin film.

Tables (3)

Tables Icon

Table 1. Comparison of gold/chitosan-GO/CdS QDs active layer via SPR method for the detection of Co2+ with previous reports.

Tables Icon

Table 2. Values of FWHM and DA of different concentration of Co2+.

Tables Icon

Table 3. Fitted values of Freundlich, Langmuir and Sips parameters for the adsorption of Co2+ on the gold/chitosan-GO/CdS QDs active layer.

Equations (4)

Equations on this page are rendered with MathJax. Learn more.

S N R = Δ θ S P R F W H M = Δ θ S P R D A
Δ θ s a t = K f C n
Δ θ s a t = Δ θ m a x K L C 1 + K L C
Δ θ s a t = Δ θ m a x ( K s C ) n 1 + ( K s C ) n

Metrics