The graphene nanopowder for electro-catalytic oxidation of dopamine and uric acid in the presence of ascorbic acid

The graphene nanopowder for electro-catalytic oxidation of dopamine and uric acid in the presence of ascorbic acid has been investigated by cyclic voltammetry, linear polarization and chronoamperometry. The graphene nanopowder modified electrode was prepared using the drop coating method, which displayed excellent electrocatalytic activity towards the oxidation of dopamine and uric acid compared with the bare glassy carbon electrode in phosphate buffer solution at pH = 7.0. Linear responses for dopamine and uric acid were obtained in the ranges of 3.3 μmol/L to 249.1 μmol/L and 6.7 μmol/L to 386.3 μmol/L with detection limits of 1.5 μmol/L and 2.7 μmol/L (S/N = 3), respectively. The response time was less than 2 s in case of dopamine and 3 s in case of uric acid, respectively. The results demonstrated that the graphene nanopowder had potential for detecting dopamine and uric acid.