Abstract

We present experimental results showing that long-period gratings in photonic crystal fibers can be used as sensitive biochemical sensors. A layer of biomolecules was immobilized on the sides of the holes of the photonic crystal fiber and by observing the shift in the resonant wavelength of a long-period grating it was possible to measure the thickness of the layer. The long-period gratings were inscribed in a large-mode area silica photonic crystal fiber with a CO2 laser. The thicknesses of a monolayer of poly-L-lysine and double-stranded DNA was measured using the device. We find that the grating has a sensitivity of approximately 1.4nm/1nm in terms of the shift in resonance wavelength in nm per nm thickness of biomolecule layer.

© 2006 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. K. L. Brogan and D. R. Walt, "Optical fiber-based sensors: application to chemical biology," Current Opinion in Chemical Biology 9, 494-500 (2005).
    [CrossRef] [PubMed]
  2. G. Gauglitz, "Direct optical sensors: principles and selected applications," Anal. Bioanal. Chem. 381, 141-155 (2005).
    [CrossRef] [PubMed]
  3. O. S. Wolfbeis, "Fiber-optic chemical sensors and biosensors," Anal. Chem. 76, 3269-3283 (2004).
    [CrossRef] [PubMed]
  4. B. Lee, "Review of the present status of optical fiber sensors," Opt. Fiber Technol. 9, 57-79 (2003).
    [CrossRef]
  5. S. W. James and R. P. Tatam, "Optical fibre long-period grating sensors: Characteristics and application," Meas. Sci. Technol. 14, R49-R61 (2003).
    [CrossRef]
  6. M. P. DeLisa, Z. Zhang, M. Shiloach, S. Pilevar, C. C. Davis, J. S. Sirkis, andW. E. Bentley, "Evanescent Wave Long-Period Fiber Bragg Grating as an Immobilized Antibody Biosensor," Anal. Chem. 72, 2895-2900 (2000).
    [CrossRef] [PubMed]
  7. R. Slavik, J. Homola, and J. Ctyroky, "Single-mode optical fiber surface plasmon resonance sensor," Sens. Actuators B 54, 74-79 (1999).
    [CrossRef]
  8. Y. Zhang, H. Shibru, K. L. Cooper, and A. B. Wang, "Miniature fiber-optic multicavity Fabry-Perot interferometric biosensor," Opt. Lett. 30, 1021-1023 (2005).
    [CrossRef] [PubMed]
  9. P. Russell, "Review: Photonic Crystal Fibers," Science 299, 358-362 (2003).
    [CrossRef] [PubMed]
  10. J. C. Knight, T. A. Birks, P. S. J. Russell, and D. M. Atkin, "All-silica single-mode optical fiber with photonic crystal cladding," Opt. Lett. 21, 1547-1549 (1996).
    [CrossRef] [PubMed]
  11. J. M. Fini, "Microstructure fibres for optical sensing in gases and liquids," Meas. Sci. Technol. 15, 1120-1128 (2004).
    [CrossRef]
  12. M. A. van Eijkelenborg, M. C. J. Large, A. Argyros, J. Zagari, S. Manos, N. Issa, I. Bassett, S. Fleming, R. C. McPhedran, C. M. de Sterke, and N. A. P. Nicorovici, "Microstructured polymer optical fibre," Opt. Express 9, 319 - 327 (2001).
    [CrossRef] [PubMed]
  13. F. M. Cox, A. Argyros, and M. C. J. Large, "Ultracompact biochemical sensor built with two-dimensional photonic crystal microcavity," Opt. Express 14, 4135 (2006).
    [CrossRef] [PubMed]
  14. J. B. Jensen, L. H. Pedersen, P. E. Hoiby, L. B. Nielsen, T. P. Hansen, J. R. Folkenberg, J. Riishede, D. Noordegraaf, K. Nielsen, A. Carlsen, and A. Bjarklev, "Photonic crystal fiber based evanescent-wave sensor for detection of biomolecules in aqueous solutions," Opt. Lett. 29, 1974-1976 (2004).
    [CrossRef] [PubMed]
  15. J. B. Jensen, P. E. Hoiby, G. Emiliyanov, O. Bang, L. H. Pedersen, and A. Bjarklev, "Selective detection of antibodies in microstructured polymer optical fibers," Opt. Express 13, 5883-5889 (2005).
    [CrossRef] [PubMed]
  16. E. Chow, A. Grot, L. Mirkarimi, M. Sigalas, and G. Girolami, "Ultracompact biochemical sensor built with two-dimensional photonic crystal microcavity," Opt. Lett. 29, 1093-1095 (2004).
    [CrossRef] [PubMed]
  17. T.W. Koo, S. Chan, and A. A. Berlin, "Single-molecule detection of biomolecules by surface-enhanced coherent anti-Stokes Raman scattering," Opt. Lett. 30, 1024-1026 (2005).
    [CrossRef] [PubMed]
  18. R. Karlsson, A. Michaelsson, and L. Mattsson, "Kinetic-Analysis of Monoclonal Antibody-Antigen Interactions with a New Biosensor Based Analytical System," J. Immunol. Methods 145, 229-240 (1991).
    [CrossRef] [PubMed]
  19. D. A. Markov, K. Swinney, and D. J. Bornhop, "Label-free molecular interaction determinations with nanoscale interferometry," J. Am. Chem. Soc. 126, 16,659-16,664 (2004).
    [CrossRef]
  20. Http://www.crystal-fibre.com.
  21. G. Kakarantzas, T. A. Birks, and P. S. J. Russell, Opt. Lett. 27, 1013 (2002).
    [CrossRef]
  22. Y. Zhu, P. Shum, J.-H. Chong, M. K. Rao, and C. Lu, "Deep-notch, ultracompact long-period grating in a largemode- area photonic crystal fiber," Opt. Lett. 28, 2467-2469 (2003).
    [CrossRef] [PubMed]
  23. P. D. Sawant, G. S. Watson, S. Myhra, and D. V. Nicolau, "Hierarchy of DNA immobilization and hybridization on poly-L-lysine using an atomic force microscopy study," J. Nanosci. Nanotechnol. 5, 951-957 (2005).
    [CrossRef] [PubMed]
  24. L. Rindorf, P. E. Hoiby, J. B. Jensen, L. H. Pedersen, O. Bang, and O. Geschke, "Biomolecule detection with integrated evanescent-wave microstructured optical fibre sensor," Anal. Bioanal. Chem.1-6 (Jan 2006)
    [PubMed]
  25. <a href="Http://www.nuncbrand.com">Http://www.nuncbrand.com</a>.

2006 (2)

L. Rindorf, P. E. Hoiby, J. B. Jensen, L. H. Pedersen, O. Bang, and O. Geschke, "Biomolecule detection with integrated evanescent-wave microstructured optical fibre sensor," Anal. Bioanal. Chem.1-6 (Jan 2006)
[PubMed]

F. M. Cox, A. Argyros, and M. C. J. Large, "Ultracompact biochemical sensor built with two-dimensional photonic crystal microcavity," Opt. Express 14, 4135 (2006).
[CrossRef] [PubMed]

2005 (6)

Y. Zhang, H. Shibru, K. L. Cooper, and A. B. Wang, "Miniature fiber-optic multicavity Fabry-Perot interferometric biosensor," Opt. Lett. 30, 1021-1023 (2005).
[CrossRef] [PubMed]

T.W. Koo, S. Chan, and A. A. Berlin, "Single-molecule detection of biomolecules by surface-enhanced coherent anti-Stokes Raman scattering," Opt. Lett. 30, 1024-1026 (2005).
[CrossRef] [PubMed]

J. B. Jensen, P. E. Hoiby, G. Emiliyanov, O. Bang, L. H. Pedersen, and A. Bjarklev, "Selective detection of antibodies in microstructured polymer optical fibers," Opt. Express 13, 5883-5889 (2005).
[CrossRef] [PubMed]

P. D. Sawant, G. S. Watson, S. Myhra, and D. V. Nicolau, "Hierarchy of DNA immobilization and hybridization on poly-L-lysine using an atomic force microscopy study," J. Nanosci. Nanotechnol. 5, 951-957 (2005).
[CrossRef] [PubMed]

K. L. Brogan and D. R. Walt, "Optical fiber-based sensors: application to chemical biology," Current Opinion in Chemical Biology 9, 494-500 (2005).
[CrossRef] [PubMed]

G. Gauglitz, "Direct optical sensors: principles and selected applications," Anal. Bioanal. Chem. 381, 141-155 (2005).
[CrossRef] [PubMed]

2004 (5)

O. S. Wolfbeis, "Fiber-optic chemical sensors and biosensors," Anal. Chem. 76, 3269-3283 (2004).
[CrossRef] [PubMed]

J. M. Fini, "Microstructure fibres for optical sensing in gases and liquids," Meas. Sci. Technol. 15, 1120-1128 (2004).
[CrossRef]

D. A. Markov, K. Swinney, and D. J. Bornhop, "Label-free molecular interaction determinations with nanoscale interferometry," J. Am. Chem. Soc. 126, 16,659-16,664 (2004).
[CrossRef]

E. Chow, A. Grot, L. Mirkarimi, M. Sigalas, and G. Girolami, "Ultracompact biochemical sensor built with two-dimensional photonic crystal microcavity," Opt. Lett. 29, 1093-1095 (2004).
[CrossRef] [PubMed]

J. B. Jensen, L. H. Pedersen, P. E. Hoiby, L. B. Nielsen, T. P. Hansen, J. R. Folkenberg, J. Riishede, D. Noordegraaf, K. Nielsen, A. Carlsen, and A. Bjarklev, "Photonic crystal fiber based evanescent-wave sensor for detection of biomolecules in aqueous solutions," Opt. Lett. 29, 1974-1976 (2004).
[CrossRef] [PubMed]

2003 (4)

Y. Zhu, P. Shum, J.-H. Chong, M. K. Rao, and C. Lu, "Deep-notch, ultracompact long-period grating in a largemode- area photonic crystal fiber," Opt. Lett. 28, 2467-2469 (2003).
[CrossRef] [PubMed]

P. Russell, "Review: Photonic Crystal Fibers," Science 299, 358-362 (2003).
[CrossRef] [PubMed]

B. Lee, "Review of the present status of optical fiber sensors," Opt. Fiber Technol. 9, 57-79 (2003).
[CrossRef]

S. W. James and R. P. Tatam, "Optical fibre long-period grating sensors: Characteristics and application," Meas. Sci. Technol. 14, R49-R61 (2003).
[CrossRef]

2002 (1)

2001 (1)

2000 (1)

M. P. DeLisa, Z. Zhang, M. Shiloach, S. Pilevar, C. C. Davis, J. S. Sirkis, andW. E. Bentley, "Evanescent Wave Long-Period Fiber Bragg Grating as an Immobilized Antibody Biosensor," Anal. Chem. 72, 2895-2900 (2000).
[CrossRef] [PubMed]

1999 (1)

R. Slavik, J. Homola, and J. Ctyroky, "Single-mode optical fiber surface plasmon resonance sensor," Sens. Actuators B 54, 74-79 (1999).
[CrossRef]

1996 (1)

1991 (1)

R. Karlsson, A. Michaelsson, and L. Mattsson, "Kinetic-Analysis of Monoclonal Antibody-Antigen Interactions with a New Biosensor Based Analytical System," J. Immunol. Methods 145, 229-240 (1991).
[CrossRef] [PubMed]

Argyros, A.

Atkin, D. M.

Bang, O.

L. Rindorf, P. E. Hoiby, J. B. Jensen, L. H. Pedersen, O. Bang, and O. Geschke, "Biomolecule detection with integrated evanescent-wave microstructured optical fibre sensor," Anal. Bioanal. Chem.1-6 (Jan 2006)
[PubMed]

J. B. Jensen, P. E. Hoiby, G. Emiliyanov, O. Bang, L. H. Pedersen, and A. Bjarklev, "Selective detection of antibodies in microstructured polymer optical fibers," Opt. Express 13, 5883-5889 (2005).
[CrossRef] [PubMed]

Bassett, I.

Berlin, A. A.

Birks, T. A.

Bjarklev, A.

Bornhop, D. J.

D. A. Markov, K. Swinney, and D. J. Bornhop, "Label-free molecular interaction determinations with nanoscale interferometry," J. Am. Chem. Soc. 126, 16,659-16,664 (2004).
[CrossRef]

Brogan, K. L.

K. L. Brogan and D. R. Walt, "Optical fiber-based sensors: application to chemical biology," Current Opinion in Chemical Biology 9, 494-500 (2005).
[CrossRef] [PubMed]

Carlsen, A.

Chan, S.

Chong, J.-H.

Chow, E.

Cooper, K. L.

Cox, F. M.

Ctyroky, J.

R. Slavik, J. Homola, and J. Ctyroky, "Single-mode optical fiber surface plasmon resonance sensor," Sens. Actuators B 54, 74-79 (1999).
[CrossRef]

Davis, C. C.

M. P. DeLisa, Z. Zhang, M. Shiloach, S. Pilevar, C. C. Davis, J. S. Sirkis, andW. E. Bentley, "Evanescent Wave Long-Period Fiber Bragg Grating as an Immobilized Antibody Biosensor," Anal. Chem. 72, 2895-2900 (2000).
[CrossRef] [PubMed]

de Sterke, C. M.

DeLisa, M. P.

M. P. DeLisa, Z. Zhang, M. Shiloach, S. Pilevar, C. C. Davis, J. S. Sirkis, andW. E. Bentley, "Evanescent Wave Long-Period Fiber Bragg Grating as an Immobilized Antibody Biosensor," Anal. Chem. 72, 2895-2900 (2000).
[CrossRef] [PubMed]

Emiliyanov, G.

Fini, J. M.

J. M. Fini, "Microstructure fibres for optical sensing in gases and liquids," Meas. Sci. Technol. 15, 1120-1128 (2004).
[CrossRef]

Fleming, S.

Folkenberg, J. R.

Gauglitz, G.

G. Gauglitz, "Direct optical sensors: principles and selected applications," Anal. Bioanal. Chem. 381, 141-155 (2005).
[CrossRef] [PubMed]

Geschke, O.

L. Rindorf, P. E. Hoiby, J. B. Jensen, L. H. Pedersen, O. Bang, and O. Geschke, "Biomolecule detection with integrated evanescent-wave microstructured optical fibre sensor," Anal. Bioanal. Chem.1-6 (Jan 2006)
[PubMed]

Girolami, G.

Grot, A.

Hansen, T. P.

Hoiby, P. E.

Homola, J.

R. Slavik, J. Homola, and J. Ctyroky, "Single-mode optical fiber surface plasmon resonance sensor," Sens. Actuators B 54, 74-79 (1999).
[CrossRef]

Issa, N.

James, S. W.

S. W. James and R. P. Tatam, "Optical fibre long-period grating sensors: Characteristics and application," Meas. Sci. Technol. 14, R49-R61 (2003).
[CrossRef]

Jensen, J. B.

Kakarantzas, G.

Karlsson, R.

R. Karlsson, A. Michaelsson, and L. Mattsson, "Kinetic-Analysis of Monoclonal Antibody-Antigen Interactions with a New Biosensor Based Analytical System," J. Immunol. Methods 145, 229-240 (1991).
[CrossRef] [PubMed]

Knight, J. C.

Koo, T.W.

Large, M. C. J.

Lee, B.

B. Lee, "Review of the present status of optical fiber sensors," Opt. Fiber Technol. 9, 57-79 (2003).
[CrossRef]

Lu, C.

Manos, S.

Markov, D. A.

D. A. Markov, K. Swinney, and D. J. Bornhop, "Label-free molecular interaction determinations with nanoscale interferometry," J. Am. Chem. Soc. 126, 16,659-16,664 (2004).
[CrossRef]

Mattsson, L.

R. Karlsson, A. Michaelsson, and L. Mattsson, "Kinetic-Analysis of Monoclonal Antibody-Antigen Interactions with a New Biosensor Based Analytical System," J. Immunol. Methods 145, 229-240 (1991).
[CrossRef] [PubMed]

McPhedran, R. C.

Michaelsson, A.

R. Karlsson, A. Michaelsson, and L. Mattsson, "Kinetic-Analysis of Monoclonal Antibody-Antigen Interactions with a New Biosensor Based Analytical System," J. Immunol. Methods 145, 229-240 (1991).
[CrossRef] [PubMed]

Mirkarimi, L.

Myhra, S.

P. D. Sawant, G. S. Watson, S. Myhra, and D. V. Nicolau, "Hierarchy of DNA immobilization and hybridization on poly-L-lysine using an atomic force microscopy study," J. Nanosci. Nanotechnol. 5, 951-957 (2005).
[CrossRef] [PubMed]

Nicolau, D. V.

P. D. Sawant, G. S. Watson, S. Myhra, and D. V. Nicolau, "Hierarchy of DNA immobilization and hybridization on poly-L-lysine using an atomic force microscopy study," J. Nanosci. Nanotechnol. 5, 951-957 (2005).
[CrossRef] [PubMed]

Nicorovici, N. A. P.

Nielsen, K.

Nielsen, L. B.

Noordegraaf, D.

Pedersen, L. H.

Pilevar, S.

M. P. DeLisa, Z. Zhang, M. Shiloach, S. Pilevar, C. C. Davis, J. S. Sirkis, andW. E. Bentley, "Evanescent Wave Long-Period Fiber Bragg Grating as an Immobilized Antibody Biosensor," Anal. Chem. 72, 2895-2900 (2000).
[CrossRef] [PubMed]

Rao, M. K.

Riishede, J.

Rindorf, L.

L. Rindorf, P. E. Hoiby, J. B. Jensen, L. H. Pedersen, O. Bang, and O. Geschke, "Biomolecule detection with integrated evanescent-wave microstructured optical fibre sensor," Anal. Bioanal. Chem.1-6 (Jan 2006)
[PubMed]

Russell, P.

P. Russell, "Review: Photonic Crystal Fibers," Science 299, 358-362 (2003).
[CrossRef] [PubMed]

Russell, P. S. J.

Sawant, P. D.

P. D. Sawant, G. S. Watson, S. Myhra, and D. V. Nicolau, "Hierarchy of DNA immobilization and hybridization on poly-L-lysine using an atomic force microscopy study," J. Nanosci. Nanotechnol. 5, 951-957 (2005).
[CrossRef] [PubMed]

Shibru, H.

Shiloach, M.

M. P. DeLisa, Z. Zhang, M. Shiloach, S. Pilevar, C. C. Davis, J. S. Sirkis, andW. E. Bentley, "Evanescent Wave Long-Period Fiber Bragg Grating as an Immobilized Antibody Biosensor," Anal. Chem. 72, 2895-2900 (2000).
[CrossRef] [PubMed]

Shum, P.

Sigalas, M.

Sirkis, J. S.

M. P. DeLisa, Z. Zhang, M. Shiloach, S. Pilevar, C. C. Davis, J. S. Sirkis, andW. E. Bentley, "Evanescent Wave Long-Period Fiber Bragg Grating as an Immobilized Antibody Biosensor," Anal. Chem. 72, 2895-2900 (2000).
[CrossRef] [PubMed]

Slavik, R.

R. Slavik, J. Homola, and J. Ctyroky, "Single-mode optical fiber surface plasmon resonance sensor," Sens. Actuators B 54, 74-79 (1999).
[CrossRef]

Swinney, K.

D. A. Markov, K. Swinney, and D. J. Bornhop, "Label-free molecular interaction determinations with nanoscale interferometry," J. Am. Chem. Soc. 126, 16,659-16,664 (2004).
[CrossRef]

Tatam, R. P.

S. W. James and R. P. Tatam, "Optical fibre long-period grating sensors: Characteristics and application," Meas. Sci. Technol. 14, R49-R61 (2003).
[CrossRef]

van Eijkelenborg, M. A.

Walt, D. R.

K. L. Brogan and D. R. Walt, "Optical fiber-based sensors: application to chemical biology," Current Opinion in Chemical Biology 9, 494-500 (2005).
[CrossRef] [PubMed]

Wang, A. B.

Watson, G. S.

P. D. Sawant, G. S. Watson, S. Myhra, and D. V. Nicolau, "Hierarchy of DNA immobilization and hybridization on poly-L-lysine using an atomic force microscopy study," J. Nanosci. Nanotechnol. 5, 951-957 (2005).
[CrossRef] [PubMed]

Wolfbeis, O. S.

O. S. Wolfbeis, "Fiber-optic chemical sensors and biosensors," Anal. Chem. 76, 3269-3283 (2004).
[CrossRef] [PubMed]

Zagari, J.

Zhang, Y.

Zhang, Z.

M. P. DeLisa, Z. Zhang, M. Shiloach, S. Pilevar, C. C. Davis, J. S. Sirkis, andW. E. Bentley, "Evanescent Wave Long-Period Fiber Bragg Grating as an Immobilized Antibody Biosensor," Anal. Chem. 72, 2895-2900 (2000).
[CrossRef] [PubMed]

Zhu, Y.

Anal. Bioanal. Chem. (2)

G. Gauglitz, "Direct optical sensors: principles and selected applications," Anal. Bioanal. Chem. 381, 141-155 (2005).
[CrossRef] [PubMed]

L. Rindorf, P. E. Hoiby, J. B. Jensen, L. H. Pedersen, O. Bang, and O. Geschke, "Biomolecule detection with integrated evanescent-wave microstructured optical fibre sensor," Anal. Bioanal. Chem.1-6 (Jan 2006)
[PubMed]

Anal. Chem. (2)

O. S. Wolfbeis, "Fiber-optic chemical sensors and biosensors," Anal. Chem. 76, 3269-3283 (2004).
[CrossRef] [PubMed]

M. P. DeLisa, Z. Zhang, M. Shiloach, S. Pilevar, C. C. Davis, J. S. Sirkis, andW. E. Bentley, "Evanescent Wave Long-Period Fiber Bragg Grating as an Immobilized Antibody Biosensor," Anal. Chem. 72, 2895-2900 (2000).
[CrossRef] [PubMed]

Current Opinion in Chemical Biology (1)

K. L. Brogan and D. R. Walt, "Optical fiber-based sensors: application to chemical biology," Current Opinion in Chemical Biology 9, 494-500 (2005).
[CrossRef] [PubMed]

J. Am. Chem. Soc. (1)

D. A. Markov, K. Swinney, and D. J. Bornhop, "Label-free molecular interaction determinations with nanoscale interferometry," J. Am. Chem. Soc. 126, 16,659-16,664 (2004).
[CrossRef]

J. Immunol. Methods (1)

R. Karlsson, A. Michaelsson, and L. Mattsson, "Kinetic-Analysis of Monoclonal Antibody-Antigen Interactions with a New Biosensor Based Analytical System," J. Immunol. Methods 145, 229-240 (1991).
[CrossRef] [PubMed]

J. Nanosci. Nanotechnol. (1)

P. D. Sawant, G. S. Watson, S. Myhra, and D. V. Nicolau, "Hierarchy of DNA immobilization and hybridization on poly-L-lysine using an atomic force microscopy study," J. Nanosci. Nanotechnol. 5, 951-957 (2005).
[CrossRef] [PubMed]

Meas. Sci. Technol. (2)

S. W. James and R. P. Tatam, "Optical fibre long-period grating sensors: Characteristics and application," Meas. Sci. Technol. 14, R49-R61 (2003).
[CrossRef]

J. M. Fini, "Microstructure fibres for optical sensing in gases and liquids," Meas. Sci. Technol. 15, 1120-1128 (2004).
[CrossRef]

Opt. Express (3)

Opt. Fiber Technol. (1)

B. Lee, "Review of the present status of optical fiber sensors," Opt. Fiber Technol. 9, 57-79 (2003).
[CrossRef]

Opt. Lett. (7)

Science (1)

P. Russell, "Review: Photonic Crystal Fibers," Science 299, 358-362 (2003).
[CrossRef] [PubMed]

Sens. Actuators B (1)

R. Slavik, J. Homola, and J. Ctyroky, "Single-mode optical fiber surface plasmon resonance sensor," Sens. Actuators B 54, 74-79 (1999).
[CrossRef]

Other (2)

Http://www.crystal-fibre.com.

<a href="Http://www.nuncbrand.com">Http://www.nuncbrand.com</a>.

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 (4)

Fig. 1.
Fig. 1.

End facet of the large mode area LMA10 [20] photonic crystal fiber used in the presented experiments. The fiber has the structural parameters, relative (absolute) hole size d/Λ = 0.47 and inter-hole center distance (pitch) Λ = 7.2μm.

Fig. 2.
Fig. 2.

(a) A hole of a photonic crystal fiber. The side is coated with poly-L-lysine (PLL) and DNA in monolayers of various thickness (t DNA and t PLL) and refractive indices (n r,DNA and n r,PLL). The thickness of the biofilms is vastly exaggerated compared to the hole diameter. (b) The molecular structure of poly-L-lysine (red & black) with positive charges immobilized onto the negatively charged silica surface (SiO2). The negatively charged DNA (green) is immobilized on the poly-L-lysine

Fig. 3.
Fig. 3.

The sensitivity of the water filled PCF-LPG on temperature. Experimental resonant wavelength as function of temperature (crosses) with an interpolated curve. Refractive index of water as function of temperature, nr (T,λres (T))

Fig. 4.
Fig. 4.

(a) The experimental transmission spetra for PBS (phosphate buffered saline solution), PLL (poly-L-lysine) and double-stranded DNA. The curve for PBS shows the absolute transmission in dBm, The two other curves, PLL, DNA, are offset on the y-axis for clarity. (b) Close up of dotted rectangle in (a). The transmission spetra for PBS (circles), PLL (diamonds) and double stranded DNA (crosses). Each spectrum has been interpolated with a curve. The curve for PBS shows the absolute transmission in dBm, The two other curves, PLL, DNA, are offset on the y-axis for clarity

Equations (1)

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

λ = Λ G ( n co eff ( λ ) n cl eff ( λ ) ) ,

Metrics