Electrochemical immunosensors

Abstract

Using a novel pipette anodization, platinum disk electrodes were fabricated and subsequently applied for the detection of glucose oxidase (GOx). The sensing mechanism depends on the blocking of alumina pore channels when the antigen molecules bind to antibody molecules attached to the channel walls, impeding the diffusion of redox probe, ferrocenemethanol, towards the sensing platinum wire overlaid by the alumina film. A low detection limit of 100 ng L-1 was achieved for GOx. When the same sensor platform was used for the determination of West Nile Virus domain III protein (WNV D-III) and particles, low detection limits of 4 ng L-1 and ca. 2 particles mL-1 were achieved, respectively. The potential of the immunosensor for real sample detection was also evaluated. Finally, the activity of IgG-bound GOx adsorbed on glass and gold substrates was studied using scanning electrochemical microscopy (SECM).