Hyperspectral TERS Imaging Reveals Strain Heterogeneity in Individual Nanoplastic Particles.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41384812.
- Also identified by DOI 10.1021/acs.nanolett.5c05003 and PMC identifier 12751103.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Nanoplastics pose growing environmental and health risks, yet their label-free, nondestructive detection and characterization, especially at the single-particle level, remain challenging. Here, we deploy AFM-based tip-enhanced Raman spectroscopy (AFM-TERS) to chemically characterize individual polystyrene (PS) nanoplastic particles via hyperspectral imaging under ambient conditions. TERS spectra from nanoparticles as small as 32 nm establish reliable single-particle sensitivity beyond the optical diffraction limit. Furthermore, hyperspectral TERS maps reveal pronounced intraparticle heterogeneity, reflected spatially as varying red-/blue-shifts of PS marker bands with broad frequency distributions, without any systematic dependence on particle size. Correlative AFM phase imaging exposes nanoscale variations in local stiffness indicating strain heterogeneity as the origin of the spectral shifts. These results demonstrate that AFM-TERS enables single-particle mapping of intraparticle heterogeneity in nanoplastics. This offers new possibilities to identify nanoplastics with molecular specificity and monitor chemical transformations at the single-particle level within complex biological and environmental matrices.