Molecularly imprinted Photoelectrochemical sensor for Escherichia coli based on Cu:ZIF-8/KZ3TTz heterojunction

Herein, a signal stable molecularly imprinted photoelectrochemical (MIP-PEC) sensing platform was designed to sensitively detect Escherichia coli by incorporating polythiophene film with Cu: ZIF-8/KZ3TTz heterojunction . Attributed to the formation of a staggered type II heterostructure between KZ3TTz and Cu: ZIF-8 semiconductors, the Cu: ZIF-8/KZ3TTz heterojunction exhibited stable and significant cathode PEC response. Impressively, selective MIP film was grown on the surface of Cu: ZIF-8/KZ3TTz/GCE by electro-polymerization of 2,2-Dimethyl-5-(3-thienyl)-1,3-dioxane-4,6-dione (DTDD) in the presence of E. coli . After removing E. coli , more electrons were transferred to the electrolyte solution through the imprinting cavity on the MIP film, which was eliminated by O 2 in the electrolyte, causing further enhancement of the cathode PEC response. On the contrary, when the imprinted cavity was filled with E. coli , the cathodic PEC response gradually decreased due to steric hindrance effect. The sensor showed excellent linearity in the range of 10 1 to 10 8  CFU/mL with a detection limit of 4.09 CFU/mL (S/N = 3). This strategy offered a novel approach for pathogenic bacteria detection in food safety and environmental monitoring