Monitoring nanoplastic aging in situ by moth-eye mimic plasmonic substrates

Micro-nano plastics aging is crucial as it determines the environmental fate of each plastic particle, yet few studies involved in situ aging of nanoplastics. Herein, we utilized nanosphere lithography combined with goldnanorod assembly to prepare a moth-eye mimic plasmonic substrate featuring excellent SERS performance. The substrate was applied to in situ characterize the degradation process of PS nanoplastics during UV aging. Raman spectra evidence that the substrate is sensitive to superficial chemical changes of PS nanoplastics at initial stage during 24 h of continuous UV aging. The disruption of the benzene ring skeleton, the oxidation of the side chains of PS nanoplastics during UV aging, and the presence of oxidized methylene straight chains were identified. Practical applications in environmental sample revealed the chemical changes of PP, PS, and PE, which confirm the great potential of this SERS substrate for aging studies of nanoplastics.