Electrochemical Determination of Endrin from Fruit Juice Samples at Glassy Carbon Electrode Modified with Fe Doped ZnO Nanomaterial

In this study, iron doped ZnO nanomaterial was synthesized by co-precipitation method and its surface properties were studied using Fourier transform infrared (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and UV-Vis spectroscopy. The characterization results confirmed that the synthesized Fe-ZnO nanoparticle exhibits good crystalline nature possessing wurtzite hexagonal phase and good optical properties. The synthesized Fe-ZnO nanomaterial modified glassy carbon electrode (Fe-ZnO/GCE) was used for the electrochemical determination of endrin pesticide in fruit juice samples. Compared to the bare glassy carbon electrode, the modified electrode, Fe-ZnO/GCE, showed remarkable electro-catalytic properties and an enhanced sensitivity for the determination of target analyte. It also exhibited a good linear response to endrin in the concentration ranging from 0.1 to 70 µM. The limit of detection (LOD) and limit of quantification (LOQ) of the method were 0.019 µM and 0.065 µM, respectively. Moreover, Fe-ZnO/GCE was selective for endrin analysis. It has also showed long-term stability, good repeatability and within-lab reproducibility. The practical utility of Fe-ZnO/GCE was applied for the determination of endrin in mango and orange juice samples. The relative recoveries of the real samples were ranged from 91.4-106.5%. The developed method could be used as good candidate for monitoring of endrin pesticides in food samples and other similar matrixes.