A Hierarchical Nanostructure-Based Surface-Enhanced Raman Scattering Sensor for Preconcentration and Detection of Antibiotic Pollutants

Abstract

A surface-enhanced Raman scattering (SERS) sensor that integrates a plasmonic nanostructure with an electrostatic preconcentration unit has been developed. The silver nanoparticles (Ag-NPs) grafted Ge nanowires (Ge-NWs) are grown onto the surface of a commercial copper grid (Cu-grid), which is usually used for transmission electron microscopy sample support. This leads to the formation of a hierarchical Ag-NPs@Ge-NWs@Cu-grid substrate, which plays dual roles, i.e., preconcentration of analytes and amplification of SERS signal. This SERS detection platform based on the Ag-NPs@Ge-NWs@Cu-grid substrate is able to selectively detect polar analytes such as antibiotic pollutants. This SERS sensor has achieved a limit of detection of 2.4 x 10(-9)m for 6-aminopenicillanic acid and 0.9 x 10(-9)m for penicillin G, respectively. This work has demonstrated a promising SERS detection platform for monitoring polar SERS-active pollutants in the aquatic environment.