Ni1Zn1-xLayFe2-yO4@rGO nanocomposite as electrochemical sensor for simultaneous analysis of food colorants-sunset yellow and tartrazine

It is crucial to regulate the usage of the synthetic colorants in the food products, as they may have negative effects on human health. In this study, the synthesis of La3+ substituted nickel zinc spinel ferrite nanoparticles (NPs) decorated on the reduced graphene oxide (La3+/Ni0.75Zn0.25Fe2O4@rGO) using sol–gel auto-combustion and ultra-sonication routes is reported. The formation of the synthesized samples was characterized by the advanced technical tools. The diffraction studies confirmed the formation of a face centered cubic spinel structure for La3+/Ni0.75Zn0.25Fe2O4 NPs. The microscopic analysis revealed an interplanar distance of 0.79 nm for the synthesized nanocomposite. The cyclic voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) were used to assess the electrochemical performance of the electrodes and then applied for the simultaneous analysis of Sunset Yellow (SY) and Tartrazine (TZ). The result of the voltammetric examination revealed the formation of two well-resolved anodic peaks with characterized partition potential for electrochemical assurance of SY and TZ, which guaranteed that concurrent assurance of both colorants. On the voltammetric response of SY and TZ, the effects of experimental parameters such as pH, analyte concentration, and scan rate are reported. The synergetic effect of Ni0.75Zn0.25Fe2O4, Lanthanum ion and rGO were efficiently improved the electrochemical behavior of SY and TZ. The detection limits for the two dyes were found to be 0.0067 μM and 0.0048 μM respectively. The high sensitivity, selectivity, reproducibility, a straightforward fabrication process, good electrode stability, and the capacity to regenerate the electrode surface make it ideal towards the simultaneous detection of SY and TZ present in the colored food products.