Polyoxometalate-Graphene Nanocomposite Modified Electrode for Electrocatalytic Detection of Ascorbic Acid

Phosphomolybdate functionalized graphene nanocomposite (PMo12‐GS) has been successfully formed on a glassy carbon electrode (GCE) for the detection of ascorbic acid (AA). The obtained PMo12‐GS modified GCE, was characterized by cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscopy (SEM) and Fourier transform infrared (FT‐IR) spectroscopy and compared with GCE, GS modified GCE, and PMo12 modified GCE. It shows an increased current and a decrease in over‐potential of ∼210 mV. The amperometric signals are linearly proportional to the AA concentration in a wide concentration range from 1×10−6 M to 8×10−3 M, with a detection limit of 0.5×10−6 M. The PMo12‐GS modified electrode was employed for the determination of the AA level in vitamin C tablets, with recoveries between 96.3 and 100.8 %.