Fabrication of a highly sensitive new ANT/MoS2/Fe3O4/GCE nanocomposite electrochemical sensor for herbicide Paraquat residual in environmental water resources

Here, the fabrication of a new electrode based on providing an electrocatalytic substrate by a newly assembled nanocomposition is reported. Ferric oxide-molybdenum disulfide-anthracite (Fe 3 O 4 –MoS 2 –ANT) modified glassy carbon electrode (GCE) was fabricated by a simple procedure and characterized by scanning electronic microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The modified electrode was used as the sensing device for the voltammetric determination of paraquat (PQ), an important herbicide in environmental water resources. The sensor showed good electrocatalytic activity toward the reduction of PQ. We found that the electrochemical sensitivity and durability of the modified GCE enhance in the presence of ANT. Cyclic voltammetric (CV) and differential pulse voltammetry (DVP) were used and the results showed that the Fe 3 O 4 /MoS 2 /ANT composition provides excellent electrocatalytic response for the determination of PQ. The electrochemical responses of the ANT/MoS 2 /Fe 3 O 4 /GCE were investigated to find optimal conditions of scan rate, pH, type of supporting electrolyte, and response repeatability. A linear response of 0.5–180.0 µM with a correlation coefficient ( R 2 ) of 0.997 and a detection limit (LOD) of 0.03 µM of PQ were obtained under the optimized conditions. Reasonable recoveries of PQ were obtained between 93.33 and 101.95% for tested river water samples.