Plasmon Enhanced Universal SERS Detection of Hierarchical Plastics by 3D Plasmonic Funnel Metastructure

Plasmonic nanostructures have aroused tremendous excitement in extreme light matter interactions because of efficient light harvesting and nanometer field concentration, ideal for solar thermal conversion, photocatalysis, photodetection, etc. Here a 3D self-assembled plasmonic nanostructure is reported for ultrasensitive SERS detection of hierarchical micro-nano plastic pollutants ranging from 30 nm to microns by rationally integrating high density of both surface and volumetric hot spots into one structure, enabled by V-shaped close-packed bi-metallic nanoparticles with massive nanovoids across transverse and longitudinal areas. The unique bi-metallic structure of hollow nanocones can enable an enhancement factor up to 1.1 × 10⁸ as well as self-built enrichment of targeting hierarchical analytes toward the size-matched hot spot areas, resulting in not only race detection of micro-nano plastics with concentration down to 10^-8 g L^-1 but also universal adaptability to simultaneous detection of a broad range of pollutants beyond micro-nano plastics. The results offer a practical solution for trace detection of hierarchical micro-nano plastics and other mixed aqueous pollutants, demonstrating considerable potential for combating water pollution.