ZIF-67C@CeO2 Composite for the Electrochemical Non-Enzymatic Determination of Nitrite in Fish Dry Samples

Abstract

Nitrite is widely present in the human environment, and it is one of the most common nitrogenous compounds in nature. However, Nitrite is often used as a preservative in meat products even though it has always been considered a carcinogen. Herein, dimethylimidazole was used as a ligand to coordinate Co2+ to prepare a metal-organic framework material- ZIF67, then the ZIF67 was added to the prepared cerium hydroxide to produce ZIF67C@CeO2 composite via high-temperature calcination. Furthermore, a novel ZIF67C@CeO2 composite modified glassy carbon electrode (ZIF67C@CeO2/GCE) was constructed to detect nitrite in fish dried samples. Scanning electron microscopy and X-ray diffraction were used to characterize the microstructure of the ZIF-67C@CeO2 composite. The experimental condition, such as applied potentials, load mass of composite, and pH value of electrolyte were optimized by electrochemical tests. In the optimal conditions, the linear range of the sensor for detecting nitrite is 0.3–1150 μM, and the detection limit (DL) is 0.102 μM. Moreover, the sensor possesses a good anti-jamming capability, repeatability, and reproducibility. The constructed sensor- ZIF-67C@CeO2/GCE showed excellent electrochemical performance and enabled the detection of nitrite in fish dried foods.