Facile Colorimetric Nanozyme Sheet for the Rapid Detection of Glyphosate in Agricultural Products Based on Inhibiting Peroxidase-Like Catalytic Activity of Porous CoO Nanoplates.

The rapid and onsite detection of glyphosate herbicides in agricultural products is still a challenge. Herein, a novel colorimetric nanozyme sheet for the rapid detection of glyphosate has been successfully prepared through the physical adsorption of porous CoO nanoplates on a polyester fiber membrane. Glyphosate can specifically inhibit the peroxidase-mimicking catalytic activity of porous CoO nanoplates, thereby the visual detection of glyphosate can be realized by distinguishing the change in the color intensity of the established nanozyme sheet. The prepared nanozyme sheet has good sensitivity and selectivity, with a detection limit of 0.175 mg·kg for glyphosate detection just by the naked eyes. It can effectively detect glyphosate within 10 min, and the color spots can maintain more than 20 min. The nanozyme sheet is not easily affected by the external environment in detection and storage. The merits of the nanozyme sheet facilitate its practical application in the large-scale preliminary screening of glyphosate residues in agricultural products.