Quantitative and rapid detection of nanoplastics labeled by luminescent metal phenolic networks using surface enhanced Raman scattering

The rising incidence of nanoplastics contamination in environmental ecosystems has led to substantial health risks. Traditional analysis methods are suboptimal due to their inability to efficiently analyze nanoplastics at low concentrations and time-consuming operations. Herein, we developed an innovative strategy, employing luminescent metal–phenolic networks (L-MPNs) coupled with surface-enhanced Raman spectroscopy (SERS) to separate and label nanoplastics, thus facilitating rapid, sensitive and quantitative detection of nanoplastics. We used L-MPNs composed of zirconium ions, tannic acid and rhodamine B, to uniformly label diverse sizes (50-500 nm) and types of nanoplastics (i.e., polystyrene, polymethyl methacrylate, polylactic acid). Rhodamine B, serving as a Raman reporter in L-MPNs-based SERS tags can offer sufficient sensitivity for trace measurement of nanoplastics and L-MPNs labeling can also facilitate separation of nanoplastics from liquid medium. By using a portable Raman instrument, our method offers cost-effective, rapid, and field-deployable detection features with excellent sensitivity in nanoplastic analysis with a limit of detection of 0.1 ppm. Moreover, this study provides a highly promising strategy for the robust and sensitive analysis of a wide range of particle analytes through the effective labeling performance of L-MPNs when coupled with SERS techniques.