Optimized Pretreatment for Raman-Based Nanoplastics Detection

초록

Nanoplastics are widely distributed in environmental and biological systems and are increasingly recognized as a potential ecological and health concern. Reliable analysis of nanoplastics in real environmental samples requires pretreatment; however, standardized and nondestructive pretreatment strategies remain limited. In this study, we develop a simple and efficient pretreatment protocol for Raman-based nanoplastic detection of polystyrene (PS) nanoplastics. Using PS nanospheres of three nominal sizes (300, 600, 800 nm) as a standard particle, four commonly applied chemical digestion reagents (H2O2, Fenton's reagent, NaOH, and HNO3) were systematically evaluated. H2O2 effectively removed organic matter while inducing minimal alteration to polymer structure. For preconcentration, vacuum filtration combined with optimized ultrasonication achieved a recovery rate of up to 92% without causing membrane contamination. During sample preparation, freeze-drying suppressed the coffee-ring effect, and optimization of droplet volume enabled uniform particle deposition on the substrate, thereby ensuring reproducible single-particle Raman measurements. By optimizing digestion, preconcentration, and sample preparation steps, this pretreatment protocol reduces systematic biases introduced during sample preparation and provides a practical basis for standardized pretreatment of PS nanoplastics under the tested conditions.

키워드