Abstract

Microplastics (MPs) have been reported in various environmental compartments and their number is continuously increasing because of degradation into smaller fragments down to nanoplastics. Humans are exposed to these small-sized MPs through food and air with potential health consequences that still need to be determined. This requires, in the first place, efficient and detailed visualization, relocalization, and characterization of the same MPs with complementary analytical methods. Here, we show the first application of a correlative microscopy and spectroscopy workflow to MPs that meets these demands. For this purpose, standard MP particles on aluminum-coated polycarbonate membrane filters were investigated by an optical zoom microscope and a hyphenated scanning electron microscopy (SEM)-Raman system. By merging the obtained data in one software, it is possible to navigate on the entire filters’ surface and correlate at identical locations MP morphology at the spatial resolutions of electron (1.6 nm at 1 kV for the used SEM, ∼100 nm minimum MP size in this study) and optical (∼1–10 µm) microscopies with chemical identification by micro-Raman spectroscopy. Moreover, we observed that low-voltage SEM works without a conductive coating of MPs, causes no detectable charging and structural changes, and provides high-resolution surface imaging of single and clustered MP particles, thus enabling subsequent Raman measurements. We believe that further work on the accurate identification and quantification of micro- and nanoplastics in real samples can potentially profit from this workflow.

© 2020 The Author(s)

Detection and analysis of microplastics in offshore sediment by microscopic differential Raman spectroscopy

Yang Dong, Qingsheng Xue, Fengqin Lu, Fupeng Wang, and Qian Li
Appl. Opt. 61(34) 10188-10196 (2022)

Design of a confocal micro-Raman spectroscopy system and research on microplastics detection

Jitao Lu, Qingsheng Xue, Haoxuan Bai, and Nan Wang
Appl. Opt. 60(27) 8375-8383 (2021)

Limits of the detection of microplastics in fish tissue using stimulated Raman scattering microscopy

Moritz Floess, Marie Fagotto-Kaufmann, Andrea Gall, Tobias Steinle, Ingrid Ehrlich, and Harald Giessen
Biomed. Opt. Express 15(3) 1528-1539 (2024)

Identification of microplastics in a large water volume by integrated holography and Raman spectroscopy

Tomoko Takahashi, Zonghua Liu, Thangavel Thevar, Nicholas Burns, Sumeet Mahajan, Dhugal Lindsay, John Watson, and Blair Thornton
Appl. Opt. 59(17) 5073-5078 (2020)

Multi-resolution open-top light-sheet microscopy to enable efficient 3D pathology workflows

Lindsey A. Barner, Adam K. Glaser, Hongyi Huang, Lawrence D. True, and Jonathan T. C. Liu
Biomed. Opt. Express 11(11) 6605-6619 (2020)