Manganese oxide nanowire-mediated enzyme-linked immunosorbent assay

Nanomaterial-based enzyme-linked immunosorbent assay (ELISA) with sufficient sensing specificity is a useful analytical tool for the detection of toxicologically important substances in complicated biological systems. Increasing worldwide demand for nanomaterials and increasing concern on their safe development and use, require a simple, stable, and sensitive detection assay for pathogen evaluation and environmental monitoring. However, this goal is not yet achieved. A design for a hybrid MnO2 nanowire-ELISA using the sandwich assay format, which provides quantitative binding information for both a specific antibody and the pathogen, sulfate-reducing bacteria, and detects pathogen concentration, is presented. 3,3',5,5'-Tetramethylbenzidine was used as the substrate and was allowed to react with the MnO2 nanowires without H2O2 in the reaction system. The kinetic parameters were measured with the system acting as a catalytic biosensor. The effectiveness of the MnO2 nanowire-based biosensor was demonstrated by its sensitive detection of the pathogen. (C) 2011 Elsevier B.V. All rights reserved.