Efficient detection of flusilazole by an electrochemical sensor derived from MOF MIL-53(Fe) for food safety

Flusilazole is a triazole fungicide with residues that are potentially toxic to humans. It enters the human body mainly through food, although its bactericidal activity is substantial. In this study, an electrochemical sensor Fe/Fe2O3@C with a core–shell structure was constructed to efficiently detect flusilazole by annealing MIL-53(Fe) which was prepared by a simple solvothermal method. Transmission electron microscopy and scanning electron microscopy were used to characterize the apparent morphology of MIL-53(Fe) and Fe/Fe2O3@C, and their structures were further characterized by X-ray photoelectron spectroscopy, Raman spectroscopy, powder X-ray diffraction, and the mapping of elements by energy dispersive spectroscopy. The electrochemical behavior of Fe/Fe2O3@C in the detection of flusilazole was evaluated by differential pulse voltammetry under optimal conditions. The results of the study indicate that the Fe/Fe2O3@C electrochemical sensor displayed excellent detection capabilities for flusilazole, where the sensor exhibited a wide detection range from 1.00 × 10−4 to 1.00 × 10−12 mol/L with an incredibly low LOD of 593 fM, making it highly sensitive to trace amounts of flusilazole. Moreover, Fe/Fe2O3@C demonstrated superior reproducibility, stability, and resistance to interference, highlighting its reliability in practical applications. The sensor was also successfully utilized to quantitatively detect flusilazole in various real samples, which suggests that Fe/Fe2O3@C has broad-spectrum environmental resistance and can effectively and rapidly detect flusilazole residues in different types of food items and environmental matrices. The study also delved into the mechanism of Fe/Fe2O3@C for the detection of flusilazole, providing a deeper understanding of the functionality of this sensor. Overall, these findings emphasize the practical significance of Fe/Fe2O3@C as an electrochemical sensor, showcasing its potential for real-world applications in food safety and environmental monitoring.