Bioelectrochemical characteristics of glucose oxidase immobilized in a polyaniline film

Glucose biosensors have been prepared by both adsorption and electrochemical doping on/in a polyaniline film. The experimental results of the cyclic voltammograms and impedance measurements show that the characteristics of the glucose biosensor formed by electrochemical doping are different from those of the biosensor formed by adsorption. X-ray photoelectron spectroscopy (XPS) experiments reveal that the chemical shifts of N 1s and O 1s in polyaniline doped electrochemically with glucose oxidase are greater than those for adsorption, i.e, the binding force between glucose oxidase and polyaniline for electrochemical doping is stronger than that for adsorption. Glucose oxidase adsorbed on a polyaniline film desorbs more easily than that doped electrochemically in the film. The glucose biosensor formed by electrochemical doping has a high operational stability and long storage stability of 36 months. Up to now this biosensor is still working. The biosensor has been used for the determination of glucose in human blood.