Combining Submicron Spectroscopy Techniques (AFM-IR and O-PTIR) to Detect and Quantify Nanoplastics in Snow From a Utah Ski Resort

Authors

Sara L. Belontz, California State University, San MarcosFollow
Janice Brahney, Utah State UniversityFollow
Caroline E. Caplan, California State University, San Marcos
Eoghan Dillon, Photothermal Spectroscopy Corp.
Ting Yan, Photothermal Spectroscopy Corp.
Gerardo Dominguez, California State University, San MarcosFollow

Document Type

Article

Journal/Book Title/Conference

Environmental Science & Technology

Volume

59

Issue

26

Publisher

American Chemical Society

Publication Date

6-26-2025

Journal Article Version

Version of Record

Keywords

Nanoplastics, Microplastics, Spectroscopy, AFM-IR, O-PTIR, Snow

First Page

13362

Last Page

13373

Creative Commons License

This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Abstract

Atomic force microscopy-based infrared spectroscopy (AFM-IR) and optical photothermal infrared (O-PTIR) spectroscopy are cutting-edge techniques used for precise nanoscale chemical analysis, capable of detecting and characterizing particles smaller than 1 μm. In this study, we applied both techniques to analyze snow subsamples collected from Beaver Mountain, Utah. Quantification by AFM-IR identified a concentration of 1.50 × 10^–1 μg/mL of poly(3-hydroxybutyrate-co-4-hydroxybutyrate), a copolyester known for its biodegradability and biocompatibility and that was the only polymer detected. Notably, 96% of particles had thicknesses below 1 μm, with the smallest particle recorded at 14 nm in height, demonstrating the advantage of the paired AFM-IR and O-PTIR techniques to detect and identify the chemical composition of a single nanoparticle. By integrating AFM-IR and O-PTIR, we combined the spatial resolution of AFM with the chemical specificity of O-PTIR, overcoming the limitations of each technique. This dual approach enabled high-sensitivity detection of nanoplastics in complex environmental samples with no preprocessing required. This approach provides valuable insights into the dimensions and concentrations of nanoplastics in environmental samples, with broader implications for understanding their prevalence and impact.

Recommended Citation

Belontz, S., Brahney, J., Caplan, C., Dillon, E., Dominguez, G. (2025) Combining submicron spectroscopy techniques (AFM-IR and O-PTIR) to detect and quantify nanoplastics in snow from a Utah ski resort. Environmental Science and Technology, 59(26).