Electrochemical determination of endrin from fruit juice samples based on Fe-doped ZnO nanomaterial modified glassy carbon electrode

Pesticides have a vital role in agricultural production to control pests and maintain high product quality. However, they are potential pollutants, having harmful effects on humans, animals, and environments. Considering these issues, a fast, accurate, and efficient method to determine these pesticides is pivotal. In this study, iron-doped ZnO nanoparticles (Fe-ZnO NPs) were synthesized by the co-precipitation method, and used for the electrochemical determination of endrin pesticide in fruit juice samples. The synthesized materials were characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM), and UV-Vis spectroscopy. Then, Fe-ZnO-modified glassy carbon electrode (Fe-ZnO/GCE) was used to determine endrin and showed remarkable electro-catalytic properties and enhanced sensitivity for the determination of the target analyte. It was calculated that the diffusion coefficient (D) and kinetic rate constant (K) of endrin were 4.57 x 10-6 cm2 s-1 and 38.1 M-1 s-1, respectively at Fe-ZnO/GCE. It also exhibited a good linear response to endrin in concentrations ranging from 0.1 to 70 mu M. The limit of detection (LOD) and limit of quantification (LOQ) of the method were 0.019 mu M and 0.065 mu M, respectively. Moreover, Fe-ZnO/GCE was selective for endrin analysis. It has also shown good sensitivity (2.16 mu A/mu M cm-2), 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 ranged from 91.4 to 106.5%. The developed method could be used as a good candidate for monitoring endrin pesticides in food samples.Graphical abstractSchematic illustration of the preparation of Ni-polyaniline electrode for glucose sensing