Single particle detection of micro/nano plastics based on recyclable SERS sensor with two-dimensional AuNPs thin films

Micro/nano plastics (MNPs) are widely recognized as a global environmental threat. Due to the lack of viable and reliable analytical methods, the identification and visualization of microplastics , especially nanoplastics , remains difficult to achieve, especially for single particle detection. Here, this study offered a simple, high-sensitive, and low-cost technique for MNPs identification using surface-enhanced Raman scattering (SERS) based on two-dimensional AuNPs thin films . This work realized the single particle detection of polystyrene (PS) and polymethyl methacrylate (PMMA), owing to the hot spot region created by the electromagnetic amplification of two-dimensional AuNPs thin films. The SERS-active substrate had a high SERS property in the single particle detection of MNPs as small as 200 nm. Moreover, this method can be used for the SERS mapping as a rapid detection technique for MNPs. In additon, this SERS-active substrate had good stability and reusable performance after 5 cycles. These findings indicated that this SERS strategy based on two-dimensional AuNPs thin films was an efficient and rapid method to identify nanoplastics in environment. And we believed that this kind of recyclable SERS sensor may create a universal strategy for the detection of MNPs at trace level.