A self-powered cathodic molecular imprinting ultrasensitive photoelectrochemical tetracycline sensor via ZnO/C photoanode signal amplification

Quantitative determination of tetracycline (TC) in environment and foods is of great importance, as excessive residues might have negative effects on human health and environmental risks. Herein, a self-powered molecularly imprinted photoelectrochemical (PEC) sensor based on the ZnO/C photoanode and the Fe-doped CuBi₂O₄ (CBFO) photocathode is developed for the sensitive detection of TC. The photocathodic current can be amplified by the efficient electron transfer caused by the Fermi energy level gap between the photoanode and photocathode. Furthermore, molecularly imprinted polymers (MIPs) at photocathode can selectivity identify the TC templates and thus improve the specificity. Under the optimal conditions, the sensor has a linear range of 10^‒2–1.0 × 10⁵ nmol/L, and a limit of detection (LOD) of 0.007 nmol/L (S/N = 3). More crucially, the milk sample detection is carried out using the as-prepared sensor, and the outcome is satisfactory. The research gives us a novel sensing platform for quick and accurate antibiotic (like TC) in environment and food monitoring.