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 mu M to 200 mu M 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. pi-pi 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. (C) 2009 Elsevier B.V. All rights reserved.