Target-induced coordination effect mediated the oxidase-like activity of Ph-Ag nanoparticles for enzyme-free and rapid sensing of propiconazole pesticide

It is of high importance yet a challenge to devise a sensor for direct and rapid sensing of pesticides based on a target-mediated nanoenzyme activity strategy. Herein, we design an effective colorimetric sensor for enzyme-free and rapid sensing of propiconazole (PC) pesticide based on the target-induced coordination effect mediated the oxidase (OXD)-like activity of Ph-Ag nanoparticles (Ph-Ag NPs). The Ph-Ag NPs were facilely fabricated via the coordination-driven self-assembly of the ligand L-phenylalanine (L-Phe) with Ag + . The fabricated Ph-Ag NPs exhibit robust OXD-like activity that can catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) into oxidative TMB (oxTMB). Interestingly, the OXD-like activity of Ph-Ag NPs can be inhibited by PC because the Cl atoms in PC molecular coordinate with Ag + , leading to the decline in absorbance and color of the system. Based on the PC-induced coordination effect that mediates the OXD-like activity of Ph-Ag NPs, we design a colorimetric sensor for sensing of PC in the linear range of 0.1−40 μM. This sensor shows some significant superiorities for PC detection, such as simple, rapid response, low cost, and high sensitivity with a detection limit of 0.0187 μM. The potential application of this sensor has also been verified by determining the PC in food samples with a satisfactory recovery range from 86.8% to 108.0%. This study not only affords a valid method for high sensitivity detection of PC pesticide but also offers a new sight for the rational design of enzyme-free sensor for direct and rapid detection of pesticides.