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.

This perspective commemorates 50 years of surface-enhanced Raman scattering (SERS) by highlighting the paradigm shift toward rationally designed semiconductor substrates, enabling ultrasensitive and molecule-selective detection. Several enhancement strategies have been developed to effectively modulate the electronic band structure and charge transfer (CT) processes, such as energy level customization, amorphization, quasi-metallization, and morphology control, achieving high enhancement factors with good selectivity and stability. Moreover, semiconductor SERS substrates show broad prospects in the fields of bio-sensing and cancer diagnosis. Nevertheless, standardization gaps in substrate reproducibility and data comparability hinder its widespread adoption. Resolving these challenges through multi-stakeholder collaboration is essential to bridge the technology transfer gap and establish SERS as a core platform for next-generation inspection.