Colorimetric sensing array based on confinement-stabilized COF-Pt nanozymes for high-throughput multivariate identification of organophosphorus pesticides

<p indent="0mm">Residues of organophosphorus pesticides (OPs) pose potential threats to human health and the environment. In this work, a colorimetric sensor array based on covalent organic frameworks loaded with platinum nanoparticles (COF-Pt) was successfully constructed, enabling the efficient detection and differentiation of three common OPs: chlorpyrifos, glyphosate, and dimethoate. By leveraging the high specific surface area and confinement effect of COF to ensure the high dispersion/stability of Pt nanoparticles and their excellent peroxidase-like catalytic activity, the differential adsorption of COF for various OPs leads to the inhibition of catalytic activity, resulting in unique colorimetric response patterns and achieving array sensing. Combined with principal component analysis and hierarchical cluster analysis, the sensor array can not only distinguish individual OPs but also effectively identify their binary and ternary mixtures. The application of OPs identification in actual fruit and vegetable samples has verified the excellent potential of the sensor array in complex environments. This study provides a new method for the rapid, sensitive, and reliable detection and differentiation of OPs, which is of great value for food safety and environmental monitoring.