Room-Temperature Co-Precipitation Synthesis of Magnetite Nanoparticles and Application as Electrocatalytic Platform for Agricultural Pesticides Sensing in Water

This work presents a straightforward room-temperature co-precipitation method for the synthesis of magnetite nanoparticles (Fe₃O₄NPs) and application as electrocatalytic material for the simultaneous determination of diuron (DR) and thiabendazole (TBZ) pesticides in water for the first time. The Fe₃O₄NPs were synthesized using an aqueous-based approach and immobilized onto a glassy carbon electrode (GCE) surface. Comprehensive characterization using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray, cyclic voltammetry (CV), and electrochemical impedance spectroscopy have confirmed the successful formation of well-crystallized Fe₃O₄NPs with an average crystallinity size of 61.62 nm. Electrochemical studies demonstrated strong electrostatic interactions between GCE/Fe₃O₄NPs and [Ru(NH₃)₆]³⁺. The electrochemical behavior of both pesticides were established by CV, while sensing parameters were optimized through differential pulse voltammetry. Under optimal conditions, the sensor achieved detection limits of 0.398 and 0.480 μM for DR and TBZ, respectively, with good selectivity and reproducibility. The practical utility of the sensor was successfully demonstrated through analysis of real water samples, offering a cost-effective solution for environmental monitoring applications.