Green synthesis of paper-based SERS substrate for the quantitative detection of thiabendazole by wipe sampling

Over the past few decades, green analytical chemistry has gradually gained prominence worldwide due to its economic, low toxicity, and environmentally friendly characteristics. The aim of this study was to develop an eco-friendly flexible surface-enhanced Raman scattering (SERS) substrate for in situ detection of thiabendazole (TBZ). We take advantage of the reduction ability of office paper itself, achieving an in-situ reduction of AgNO3 to silver nanoparticles (Ag NPs) on paper without any additional chemical reducing agents. The investigation of the underlying mechanism reveals that aldehydes dissolved in paper play an important role in the reduction process. Reaction time, the concentration of AgNO3, and the heating temperature were optimized to achieve the best SERS performance. The prepared SERS paper had high SERS activity, good reproducibility, and stability, which was evaluated by the detection of model molecules R6G and MB. Finally, the as-prepared substrate was successfully applied to detect the TBZ residue on the surface of the apple based on a wipe sampling method. The results showed that the detection limit of TBZ was 0.097 ppm and the recoveries of TBZ in actual samples range from 91.5 % to 99.7 %. Therefore, this study could provide a new way for the green synthesis of paper-based SERS substrate to detect contaminants in fruits.