Diamond-like carbon (DLC) microelectrode for electrochemical ELISA

A diamond-like carbon (DLC) microelectrode was applied to commercial ELISA kits for medical diagnosis of HIV (human immunodeficiency virus), HBV (human hepatitis B virus), HCV (human hepatitis C virus). In this work, quantification of oxidized 3,3',5,5'-tetramethylbenzidine (TMB) was carried out by using a microelectrode made of boron-doped DLC and cyclic voltammetric analysis method without the conventional quenching step which uses sulfuric acid. The microelectrode provided well-known step-shaped graphs, and limit of detection could be improved by clear determination of electrochemical oxidative and reductive peaks. To demonstrate the applicability of DLC microelectrode to conventional ELISA kits, commercial ELISA kits for detection of HIV antigen, HBV antigen and HCV antigen were also tested. These results proved that the applicability of DLC microelectrode to practical detection is feasible. (C) 2008 Elsevier B.V. All rights reserved.