Impedimetric immunosensor using avidin-biotin for antibody immobilization

Abstract

The potentialities of an electrodeposited biotinylated polypyrrole film as an immobilisation matrix for the fabrication of impedimetric immunosensors are described. Biotinylated antibody (anti-human IgG), used as a model system, was attached to free biotin groups on the electrogenerated polypyrrole film using avidin as a coupling reagent. This immobilization method allows to obtain a highly reproducible and stable device. The resulting immunosensor has a linear dynamic range of 10-80 ng ml-1 of antigen and a detection limit of 10 pg ml-1. Furthermore, this immunosensor exhibited minor loss in response after two regeneration steps. © 2002 Elsevier Science B.V. All rights reserved.