A dual-functional SERS platform based on silver aerogel for detection of polystyrene nanoplastics in environmental water

Nanoplastics (<1 μm), as pervasive environmental contaminants, have raised significant concern owing to their high ecosystem mobility and potential biological toxicity. However, current analytical methods confront substantial limitations in detecting nanoplastics at environmentally relevant concentrations. Herein, we introduce an innovative approach by utilizing three-dimensional silver aerogel as a dual-functional platform for the evaporative enrichment and highly sensitive surface-enhanced Raman spectroscopy (SERS) detection of nanoplastics. Due to the interconnected fibrous voids of silver aerogel and its abundant plasmonic hot spots, the established SERS method can detect polystyrene (PS) nanoplastics across the size range of 50-400 nm and achieved limit of detection (LOD) values ranging from 2.47 × 10⁻⁵ to 6.62 × 10⁻⁴ mg mL⁻¹ across various particle sizes. Moreover, the silver aerogel substrate exhibited excellent signal reproducibility with intra-substrate, inter-substrate, and inter-batch relative standard deviations (RSDs) of 2.29%, 2.56%, and 2.34%, respectively. Practical performance was assessed using river water, retaining 79.8% to 99.9% of the signal intensity obtained in pure water. These results indicate that this dual-functional silver aerogel-SERS platform serves as a powerful analytical tool for the rapid identification and quantification of nanoplastics.