Engineering of coordination environment in bioinspired laccase-mimicking catalysts for monitoring of pesticide poisoning

Developing enzyme-mimicking catalysts with high catalytic activity and specificity has been a long-standing challenge. Herein we report efficient laccase-mimicking catalysts (His-Cys-Cu) that consist of atomic Cu active centers and dipeptide-organized electron transfer pathway by simulating the catalytic process of natural enzymes, exhibiting high catalytic activity and robust stability. In particular, chloride ion (bromide ions) anchored on the surface of His-Cys-Cu as recognition antenna enhances the catalytic activity and recognition specificity by regulating reaction rate and adsorption affinity toward the substrate. By harnessing the characteristic of His-Cys-Cu, stimuli-responsive hydrogel-based portable kits and chromogenic immunosensors are fabricated for monitoring pesticide biomarkers via combining high-affinity biorecognition elements. As a result, the biosensor based on His-Cys-Cu improves the limit of detection by up to 150-fold and enhances the robustness of bioapplication for on-site testing. We envision that such a modular approach provides a versatile platform for rapid profiling of a diverse range of targets by exploiting their specific enzymatic signatures.