Non-enzymatic Electrochemical Oxidation Based on AuNP/PPy/rGO Nanohybrid Modified Glassy Carbon Electrode as a Sensing Platform for Oxalic Acid

In this study, a nanohybrid of gold nanoparticle, polypyrrole, and reduced graphene oxide (AuNP/PPy/rGO) was prepared by an in-situ chemical synthesis approach. The as-prepared nanohybrid has been applied for non-enzymatic electrochemical detection of oxalic acid (OA). The nanohybrid nanocomposite material (AuNP/PPy/rGO) was characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and cyclic voltammetry (CV), and further employed as novel sensing material to quantify OA. Compared with PPy/rGO, the AuNP/PPy/rGO nanocomposite showed enhanced electrocatalytic activity towards OA oxidation. The oxidation current of OA is linear to its concentration in the range of 0.05 mM to 7 mM with a lower detection limit of 0.02 mM. The experimental results also showed that the fabricated sensor has good reproducibility (R.S.D=2.59 % for 0.5 mM, n=3), high sensitivity (91 μA/mM), excellent stability and good anti-interference property against electroactive compounds and metal ions.