Tailored construction of Ag/WO3 nanospindles modified SERS substrates: An efficient analytical assay for identification of neonicotinoids on the surface of fruits

The peel of fruits and vegetables contain toxic elements present in pesticide like neonicotinoids, whose presence cause various health issue in humans. In this regard, for the first time, we demonstrate the ultrasensitivity detection of neonicotinoids imidacloprid on the surface of grapes by a modified SERS substrate with microspheres constitution of Ag/WO3 nanospindles. Surface engineering, phase purity, thermal stability, and elemental states of the as developed nanospindles were explored by electron microscopy, XRD, XPS, spectroscopy analysis, and the detection of imidacloprid was studied through SERS. The modified SERS substrate prominently increased the efficiency of the sensing of imidacloprid, an outstanding wide range from 10(-1) to 10(-11) M, a low detection range of 3 ng/cm(2) (S/N = 3) with correlation coefficient R-2 = 0.9904, good reproducibility, and strong anti-interference ability compared to reports data. Notably, the improved sensing activity of Ag/WO3 nanospindles can be attributed to the large surface area and charge transfer behavior. Ag nanoparticles served as a high conductivity matrix while preventing WO3 from the synergistic effect as discussed in the reaction mechanism section. Finally, the projected SERS substrate has extreme potential for pesticide detection of on-site analysis which is the upcoming scenario.

Automated summary

In this study, the ultrasensitive detection of neonicotinoid imidacloprid on the surface of grapes using a modified SERS substrate was demonstrated. The improved SERS substrate significantly increased the efficiency of imidacloprid sensing and exhibited good reproducibility and strong anti-interference ability. The large surface area and charge transfer behavior of Ag/WO3 nanospindles contributed to the enhanced sensing activity.