Advances of surface-enhanced and coherent Raman scattering spectromicroscopy for micro- and nanoplastics detection

Micro- and nanoplastics (MNPs) pose increasing risks to both human health and ecological systems, driving an urgent need for sensitive and reliable analytical methods. Among existing detection techniques, Raman-based approaches are particularly attractive due to their label-free, chemically specific, and in situ analysis with high spatial resolution. Despite numerous Raman-based MNP studies, recent advances have not been systematically reviewed, especially the applications of surface-enhanced Raman scattering (SERS) spectroscopy and coherent Raman scattering (CRS) microscopy in environmental analysis. Here, we show that the primary goal of SERS studies has shifted from maximizing detection sensitivity toward developing robust, matrix-tolerant methodologies for real environmental samples. Additionally, new analytical strategies have emerged that integrate the ultrasensitive identification power of SERS with the rapid quantification and three-dimensional imaging offered by CRS microscopy. Representative experiments have demonstrated the feasibility of this multimodal framework, providing a promising route for investigating the fate and environmental impact of MNP pollution.