Modifying platinum microelectrodes with electrochemically reduced graphene oxide for application in electrochemical ascorbic acid sensor

Graphene oxide drop-casted on a platinum microelectrode was successfully changed to reduced graphene oxide by using a cyclic voltammetry method. The presence of an electrochemically reduced graphene oxide layer on the platinum electrode was proved by using scanning electron microscopy images, Raman and Fourier-transform infrared spectroscopy spectra. Cyclic voltammetry and linear sweep voltammetry results indicated that the platinum microelectrode modified with electrochemically reduced graphene oxide can be used as an electrochemical sensor for detection of ascorbic acid in aqueous solutions. In a cyclic voltammetry scan and a linear sweep voltammetry curve corresponding to the presence of ascorbic acid, a peak related to the direct oxidation of ascorbic acid appears. The electrochemical sensor based on the electrochemically reduced graphene oxide material works effectively with a detection limit of 0.04 mM, a detection linear range from 0.04 mM to 1.0 mM, a good repeatability, and especially, a rapid detection time thanks to a direct ascorbic acid detection based on the oxidation of ascorbic acid.