Direct voltammetry of colloidal graphene oxides

• Electrolyte pH and GO particle size significantly influence the voltammetry.
• Acidic pH is preferential for observation of characteristic reductions.
• Inherent redox electrochemistry is most distinct from GO nanofibres.

The direct voltammetry of aqueous colloidal graphene oxide (GO) solutions is presented in this fundamental study. Since its inception, the majority of GO electrochemistry has been centred on the use of solid-state modified electrodes whereas the voltammetry of solution-based GO species is not well known. Overall, pH and GO particle size are found to be important aspects that influence the observed results, and voltammetric profiles of nano-sized GO under acidic condition bear the closest similarities to electrode surface-modified GO. Greater knowledge of colloidal GO electrochemistry potentially allows for its future development in electrochemical sensing applications.