Constructing a novel electrochemical sensor for the detection of fenitrothion using rare-earth orthophosphate incorporated reduced graphene oxide composite

Fenitrothion (FNT), an organophosphorus insecticide widely used in agriculture, forestry, and public health initiatives, poses substantial risks to human health, the environment, and non-target organisms. Therefore, monitoring FNT's presence in the environment is critical. Recently, rare earth phosphate compounds have gained recognition in materials science, optics, and electronics, with diverse applications. In line with this trend, our research focuses on developing a novel material by incorporating gadolinium phosphate (GdPO4) into reduced graphene oxide (RGO) for FNT detection. We successfully synthesized GdPO4/RGO using a straightforward hydrothermal method, confirmed through various spectroscopic techniques. Introducing RGO significantly enhanced GdPO4's electrical conductivity; this has been confirmed through experimental techniques such as electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Electrochemical examinations confirmed the GdPO4/RGO/GCE sensor's exceptional sensitivity and selectivity for FNT. Furthermore, the sensor exhibited remarkable sensitivity (0.8802 mu A mu M-1 cm-2), a low detection limit (LOD) of 0.007 mu M, and a linear detection range of 0.01-342 mu M for FNT under optimized conditions. The effective use of our proposed sensor in detecting FNT in different water samples was evidenced by achieving a substantial recovery rate ranging from 98.3% to 98.8%.