Flexible and ultrasensitive surface-enhanced Raman scattering substrates for the pesticide detection

In this paper, a simplified method for preparing surface-enhanced Raman scattering (SERS) substrates with spin-coating is reported. The green chemical synthesis of Ag nanoparticles (NPs) is environmentally friendly without complex instruments. The Ag NPs are coated on a polydimethylsiloxane (PDMS) film by spin coating for detecting pesticides. By this method, we can get the substrate with high sensitivity. The results showed that the substrate has a strong SERS signal even the concentration of thiram (pesticide) is down to 10−9 M. Compared with the allowed residue dose in food security (10−5 M), the detection limit of thiram is lower. On the other hand, PDMS has the advantage of flexibility and transparency, it can meet the demands of the detection of analytes on irregular objects.