Jiang_2026_Food.Chem_528_151046

In this study, a dual-mode electrochemiluminescent-colorimetric (ECL-colorimetric) biosensor based on Ag/CuTb(2)O(2) nanozyme was developed for the ultrasensitive detection of trichlorfon and other organophosphorus pesticides (OPs) by inhibiting acetylcholinesterase (AChE). The Ag/CuTb(2)O(2) composite, prepared via electrospinning and in-situ growth, exhibited high conductivity and superior peroxidase-like activity, acting as a dual-signal amplifier. In the ECL mode, it immobilized Ru(bpy)(3)(2+) and boosted the co-reactant pathway; in the colorimetric mode, it catalyzed H(2)O(2)-mediated oxidation of TMB. Based on AChE inhibition, trichlorfon reduced ECL intensity by decreasing thiocholine production and enhanced colorimetric signals by consuming thiocholine. This dual-signal self-validation improved detection reliability. The sensor achieved a linear range of 1 x 10(-12)-1 x 10(-6) mol L(-1) with LOD of 3.33 x 10(-13) mol L(-1) (ECL) and 30-5000 ng mL(-1) with LOD of 10 ng mL(-1) (colorimetric). It also responded to other OPs and gave satisfactory recoveries in vegetable samples, providing a reliable method for food safety monitoring.