Plasmonic nanostructures for environmental monitoring and/or biological applications

In this work, we have identified the size of microplastics collected from Shi Lake, China, using an optical tweezer micro-Raman spectroscopy (OTMRS) system. The microplastics were classified based on their size as products of degradation of large plastic material. Most of them were in the sub-20 μm regime. On the other hand, as nanoplastics may be more extensively distributed and hazardous than larger-sized plastics, their detection is a key point. Thus, we have designed a planar metamaterial structure and have studied the near-field enhancement in order to detect and analyze nanoplastics in aquatic environments with high sensitivity and selectivity. This study paves a way to improve our knowledge of small plastics abundance and pollution in freshwater around Shi Lake.