Lewis Bases-Assisted Enhanced SERS for Ultra-Sensitive Detection of Pesticide Residues

The ability to detect pesticide residues at trace levels is crucial for ensuring consumer health and complying with regulatory standards. Herein, we constructed a hydrophobic layer SERS substrate of silver nanoparticles on the glass surface, utilizing Lewis bases to enhance the interaction between the pesticide and the substrate. This facile method enables the ultrasensitive detection of 6-benzylaminopurine (6-BA), with the lowest detection limit decreasing from 0.01 mg/L to 5´10^-5 mg/L. More importantly, the detection limit of 6-BA in bean sprouts reached 5´10^-4 mg/kg, which is 20 times lower than the allowable residue level (0.01 mg/kg) in legumes set by the EU. Furthermore, the SERS signals of several pesticides, including kinetin, carbendazim, and imidacloprid, can also be enhanced by an order of magnitude. We believe that this method expands the applicability of SERS technology for practical pesticide residue detection, offering a simpler and more sensitive means for analyzing various pesticide contaminants.