Dialdehyde Starch-Enclosed Silver Nanoparticles Substrate with Controlled-Release “Hotspots” for Ultrasensitive Sers Detection of Thiabendazole

Abstract

Pesticide residues have long been a major concern for food safety. In this study, a dialdehyde starch-enclosed silver nanoparticles (Ag NPs) composite with controlled-release “hotspots” was developed as a surface-enhanced Raman scattering (SERS) substrate. The substrate exhibited high sensitivity and excellent stability for R6G and MB with enhancement factor (EF) of 6.5108 and 9.3107, respectively. For practical application, we demonstrated sensitive detection of thiabendazole (TBZ) in or on the surface of an apple by means of two ways, i.e., detecting the analyte in solution after pretreatment and in-situ detecting the analyte by using a flexible paper-based substrate. The results demonstrated that both methods can achieve sensitive and accurate detection of TBZ with the limits of detection (LOD) of 0.052 ppm and 0.051 ppm, respectively, and the recoveries of TBZ in actual samples range from 96.80% to 105.46%. Overall, this SERS substrate shows great potential for pesticide residue detection in food.

Keywords: dialdehyde starch, controlled-release hotspots, thiabendazole, paper-based substrate