Synthesis of Nickel Vanadate Anchored on Reduced Graphene Oxide for Electrochemical Determination of Antioxidant Radical Cations of Diphenylamine H^•+

Composites fabricated from vanadate-based bimetallic materials and carbonaceous sources are gaining prominence due to their exciting dynamics. Nickel vanadate (NV) was developed in a very simple and low-cost-dependent coprecipitation method. Later, NV was anchored on reduced graphene oxide (rGO) ultrasonically to prepare a hybrid nanocomposite. The sensor aided in detecting diphenylamine H•+, an insecticide and an organic byproduct typically discharged in water bodies, leading to pollution and threatening environmental safety. Structural, chemical, and compositional characteristic analyses were carried out for the hybrid NV/rGO composite compared with NV and rGO, which demonstrated the prepared material’s physiochemical properties. The electrochemical performance of NV with the rGO-modified glassy carbon electrode (NV/rGO/GCE) was done by cyclic voltammetry and differential pulse voltammetry measurements. The as-prepared composite showed enhanced performance with a very low limit of detection of 5.42 nM in a linear range from 0.099 to 500 μM, a very high sensitivity of 11.58 μA μM–1 cm–2, good reproducibility, and an excellent selectivity as well as stability. The sensor further proved its practical feasibility in real-time analysis on fruit juice and tea leaf samples with a satisfactory recovery rate.