Application of graphene-modified electrode for selective detection of dopamine

Graphene was synthesized chemically by Hummers and Offeman method and the graphene-modified electrode was applied in selective determination of dopamine with a linear range from 5 μM to 200 μM in a large excess of ascorbic acid. Selective detection was realized in completely eliminating ascorbic acid, different from the methods based on the potential separations. π–π stacking interaction between dopamine and graphene surface may accelerate the electron transfer whereas weaken the ascorbic acid oxidation on this graphene-modified electrode. The resulted graphene-modified electrode also showed a better performance than multi-walled carbon nanotubes-modified electrode. The phenomena were considered from the elusive two-dimensional structure and unique electronic properties of graphene.