Fabrication of Electrochemical Sensor Based on Molecularly Imprinted Polymer/Zinc Oxide Nanoparticle-Nanocomposite (MIP/ZnO/CPE) for Determination of Cyanazine in Food Samples

The purpose of this research was to create an electrochemical sensor based on a nanocomposite of zinc oxide nanoparticles (ZnO NPs) and molecularly imprinted polymer (MIP) for detecting cyanazine in food samples. To make modified electrodes, ZnO NPs were electrodeposited on the surface of a carbon paste electrode (CPE), and then a MIP layer was electropolymerized on the modified CPE (MIP/ZnO/CPE). Structural studies of modified electrodes revealed the formation of ZnO NPs with hexagonal shape characteristics and a wurtzite-type structure on the CPE surface, and after electropolymerization, polymer nanoparticles were evenly dispersed on the nanostructured surface of ZnO, resulting in the formation of a rough-shaped nanocomposite. Electrochemical measurements using DPV and amperometry revealed a significant increase in MIP/ZnO/CPE electrocatalytic activity and selectivity due to the synergistic effect of ZnO and MIPs. The studies demonstrated a linear response from 0 to 120 µM, and the sensitivity of MIP/ZnO/CPE was determined to be 0.5034 µA/µM, with a limit of detection of 5nM. The MIP/ZnO/CPE as a proposed sensing system for cyanazine analysis in real samples prepared from lettuce samples was investigated, and the analytical results showed that the RSD (3.48% to 4.64%) and recovery (99.20% to 99.60%) values were appropriate for valid and accurate practical analyses in food in agricultural wastewater samples.