Colorimetric Nanosensor for the Determination of Glyphosate Herbicide in Aqueous Solutions

Abstract

Detection of pesticides depends on complex, time-consuming, and costly techniques performed only in some regions of Brazil. Thus, this study aimed to develop a sensitive, portable, easy-to-handle, and fast nanosensor to determine the presence of glyphosate in aqueous solutions. The Co(OH)2 nanostructure was synthesized, and the kinetic study of the interaction with pesticide glyphosate-based was performed. The Co(OH)2 nanostructures had a fast and effective interaction, confirmed by UV-Visible spectroscopy. Through experimental planning, the process for obtaining nanostructures has been optimized, and the nanostructures obtained were in a size range of 434.2 nm with a hexagonal nanoplate structure. The lower limit of color-based glyphosate detection was 0.178 g.L-1. It was possible to identify the herbicide in the water of the tomato and sugar cane rinse by the change of the watercolor into pink. Although the samples showed low absorbance, the color change was noticeable to the naked eye. Therefore, to synthesize a structure that allows identifying glyphosate in a colorimetric way.