Nanoenzyme sensor for rapid detection of glyphosate in self-supplying H2O2

Abstract

Glyphosate (Gly), a prevalent organophosphate pesticide, threatens environmental stability and public health due to its widespread agricultural use, necessitating advanced detection methods for food safety monitoring. To overcome the limitations of conventional pesticide residue analysis, this study introduces a colorimetric sensing method utilizing the peroxidase-like properties of Cu(II) in CuO₂ nanoparticles. The system catalyzes the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) to a blue chromogen (oxTMB) under acidic conditions, eliminating reliance on external hydrogen peroxide. The complexation of Gly with Cu²⁺ reduced the peroxidase-like activity of CuO₂, resulting in a decrease in oxTMB formation. The concentration of Gly correlated well with the system’s color rendering. Under the optimal sensing parameters, the sensor could detect Gly concentrations from 2 to 30 mg/L with a detection limit as low as 0.041 mg/L. And the sensor was coupled with the smartphone, eliminating the need for specialized equipment to quantify Gly on-site. Furthermore, the sensor also demonstrated good stability, specificity, and accuracy in real sample application. In conclusion, this sensor provided a highly sensitive and accessible solution for the rapid detection of Gly, demonstrating substantial potential to enhance food safety.