Highly sensitive SERS substrates with multi-hot spots for on-site detection of pesticide residues

Pesticide residues will be a huge threat to food security and ecological environment; therefore, there is an urgent need to achieve rapid and on-site detection of pesticide residues. Herein, a plasmonic substrate with multiple hot spots was fabricated by transferring three-dimensional (3D) Au nanoparticles (NPs) onto the polydimethylsiloxane (PDMS) membrane for highly sensitive surface-enhanced Raman scattering (SERS) detection of pesticide residues. In combination with 3D-FDTD simulations, high SERS enhancement (EF = 1.2 x 10(8)) and high detection sensitivity (LOD = 6.3 x 10(-10)& nbsp;M) were achieved, mainly due to the enhanced electromagnetic fields around the hot spots . Additionally, the PDMS-based SERS substrate held good transparency and flexibility, enabling conformal contact with non-planar surfaces and allowing the laser to penetrate the back of the analytes. Combined with a portable Raman spectrometer, the substrates holds great potential for rapid, high sensitive, and on-site detection of contaminants in food, especially for the analyte on the nonplanar surfaces.& nbsp;

Automated summary

A plasmonic substrate with multiple hot spots was fabricated for highly sensitive SERS detection of pesticide residues. The substrate achieved high SERS enhancement and detection sensitivity, and is suitable for non-planar surfaces, providing great potential for rapid, high sensitivity, and on-site detection of contaminants in food.