Covalent immobilization of glucose oxidase to poly(O-amino benzoic acid) for application to glucose biosensor

A biosensor for glucose utilizing glucose oxidase (GOX) covalently coupled to poly(o-amino benzoic acid) (PAB; a carboxy-group-functionalized polyaniline) is described. Amperometric response measurements conducted via unmediated and mediated (with ferrocene carboxylic acid and tetrathiafulvalene) reoxidation of GOX show that glucose can be detected over a wide range of concentrations. An enzyme-conducting polymer-mediator model provides for better charge transport in a biosensor. The optimal response, obtained at pH 5.5 and 300 K, lies in the 1–40 mM range. A kinetic plot yields the value of the apparent Michaelis–Menten constant, Kmapp. The operational stability of the PAB-based glucose biosensor was experimentally determined to be about 6 days.