Zinc Oxide-Reduced Graphene Oxide-based Photoelectrochemical Sensor Combined with Molecularly Imprinting Technique for Sensitive Detection of Oxytetracycline

In this work, zinc oxide -reduced graphene oxide (ZnO-rGO) nanocomposites were fabricated using hydrothermal method, and the chemical and physical properties of the synthesized ZnO-rGO were characterized by several techniques, including X-ray diffraction and Fourier transform infrared (FT-IR) spectroscopy. A molecularly imprinted photoelectrochemical sensor based on ZnO-rGO was designed for sensitive detection of oxytetracycline (OTC). Polypyrrole (PPy) film was electropolymerized onto ZnO-rGO nanocomposites and OTC molecules were imprinted on the polymer film through hydrogen bonding. After OTC molecules were eluted, the recognition sites for OTC were left on the polymer membrane, enabling the specific detection of OTC. Linear detection of OTC was achieved in the range of 0.1-200 nmol/L with the detection limit of 0.05 nmol/L (S/N=3). The sensor was successfully applied to determination of OTC in milk and honey samples, with recoveries ranging from 95% to 107%. The developed method would provide significant reference value for effective and rapid detection of other antibiotics in the foods.