Fabrication of Non-woven Fabric-Based SERS Substrate for Direct Detection of Pesticide Residues in Fruits

In surface-enhanced Raman scattering (SERS), flexible substrate plays an important role in target molecular collection from various shape surfaces and increases the analytical sensitivity. In this study, silver nanoparticles (Ag NPs) were deposited on a non-woven fabric used as an SERS substrate by self-assembly, in situ growing or the self-assembly/in situ growing combination method. 4-Aminothiophenol was selected as a model molecular for the evaluation of the SERS performance using the substrates. The Ag NPs substrate prepared by self-assembly/in situ growing method presented the best Raman enhancement effect and its enhancement factor was estimated as high as 3.5 x 10(6). The substrate was applied to the determination of four pesticide residues on the surfaces of fruit samples through wipe sampling, and the results revealed the good reproducibility of SERS responses and high detection sensitivity. The prepared flexible substrate was simple to fabricate and environmentally friendly. It could be expected to be a useful tool in rapid on-site test of pesticide residues on fruit surfaces because of its high sensitivity, convenience and non-destructive characteristics.