A novel electrochemical biosensor based on hemin functionalized graphene oxide sheets for simultaneous determination of ascorbic acid, dopamine and uric acid

Graphene oxide (GO) has been demonstrated to be functionalized by hemin without any other reducing agents and the hemin functionalized graphene oxide (H-GO) hybrid nanomaterial was obtained under the condition of sonication, which could be ascribed to the pi-pi stacking and cation-pi interactions between GO and hemin molecules. H-GO composite, characterized by scanning electron microscopy and UV-vis absorption spectroscopy, was used for preparation of the modified electrode considering its great electrocatalytic activity, large surface area, and abundant active sites. Due to the unique structure and excellent properties, H-GO modified glassy carbon electrode (GCE) showed high electrocatalytic activities for the oxidation of ascorbic acid, dopamine, and uric acid, achieving the simultaneous determination for those three different kinds of biomolecules with detection limits of 0.3, 0.17, and 0.17 mu mol L-1 (S/N = 3), respectively. In addition, the proposed biosensor exhibited high selectivity and good stability, which could be applied for the electrochemical determination in practical samples with satisfying results. (C) 2014 Elsevier B.V. All rights reserved.