Precise point-of-care diagnostics of pesticide exposure by portable chip.

Pesticide exposure is a significant public health concern. Efficient and rapid monitoring of pesticide exposure can promptly screen poisoning victims, but current tools often suffer from poor enzyme-induced stability and limited generalizability, limiting their practical application. Herein, we report a robust diagnostic chip for the point-of-care detection of pesticide exposure by constructing Cu/DNA hybrid nanozyme (Cu-DEHN)-based hydrogel discs as modular sensing units. The Cu-DEHN exhibits precisely tunable enzymatic activity, offering superior stability compared to conventional biological enzymes, thereby ensuring reliable sensor operation. The combination of Cu-DEHN-mediated catalysis and pralidoxime iodide-triggered enzymatic reactivation was employed to establish an individual acetylcholinesterase (AChE) baseline, which overcomes the critical drawback of the population-based AChE baseline-induced misdiagnosis. The portable diagnostic chip enables real-time acquisition and analysis of colorimetric signals via a smartphone application (APP), which converts visual inputs into quantitative data for pesticide exposure assessment. This platform allows for sensitive detection of low-dose exposures and improves the accuracy of exposure evaluation, offering a reliable tool for environmental monitoring, occupational health surveillance, and personalized health management.