Synthesis and characterization of zinc tungstate/rGO composite for dopamine sensing

Here we fabricated a non-enzymatic, low cost electrochemical sensor using zinc tungstate modified reduced graphene oxide (ZnWO4/rGO) nanocomposite for the electrochemical detection of dopamine (DA). The synthesis of the ZnWO4/rGO composite was carried out using the co-precipitation method. The physical and morphological properties of pristine zinc tungstate (ZnWO4), reduced graphene oxide (rGO) and ZnWO4/rGO composites were studied using the X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray analysis (EDAX), Transmisson Electron Microscopy (TEM) and Raman spectroscopic analysis methods. The electrochemical analyses were carried out using Cyclic Voltammetry (CV), Impedance analysis and Differential Pulse Voltametric (DPV) techniques. Electrochemical investigations indicate that the incorporation of reduced graphene oxide (rGO) enhances the electrochemical activity of ZnWO4 and hence the electrochemical sensing ability of Dopamine (DA). The DPV response of ZnWO4/rGO composite towards the detection of dopamine ranging from 10 µM to 100 µM concentrations were studied and revealed a high sensitivity with a correlation coefficient (R2) of 0.9967. Interferences were also studied in the presence of different analytes such as Ascorbic Acid (AA), Creatine, Glycine and Glucose.