Coherently designed sustainable SERS active substrate of Ag/TiO2 hybrid nanostructures for excellent ultrasensitive detection of chlorpyrifos pesticide on the surface of grapes and tomatoes

Abstract

Pesticide residues contain extremely noxious elements and are found on the surface of fruits which cause serious problems to human health even at very low concentrations. From this, we developed a facile strategy and scientifically confirmed the structure, surface engineering, and spectroscopy properties of Ag/TiO2 hybrid nanostructures (nanoplates, nanorods) modified SERS active substrate for detection of chlorpyrifos on the surface of grapes and tomatoes via paste, peel off, and paste again approach. Benefiting from it, Ag/TiO2 nanorods as SERS active substrate exposed a significant enhancement for ultrasensitive performance with a dynamic linear range of 10−2 to 10-9 M. The low detection limit (LOD) was found to be 2 ng/cm2 for grapes and 5 ng/cm2 for tomatoes based on signal to noise ratio (S/N=3) with correlation coefficient R2 = 0.9983 and 0.9966, which lower than the reported values. Interestingly, the Ag/TiO2 modified SERS active sensor was able to demonstrate excellent ultra-sensitivity, reusability for the real sample analysis and could cheer up the commercial sensor for on-site detection of pesticide on fruits and vegetables in the near scenario.