DIRECT ELECTRON-TRANSFER REACTION OF GLUCOSE-OXIDASE AT BARE SILVER ELECTRODES AND ITS APPLICATION IN ANALYSIS

The direct electron transfer reaction of glucose oxidase (GOx) at a ba re silver electrode is verified. The electron transfer number n = 2, e lectron transfer coefficient alpha = 0.45 and rate constant of the ele ctrochemical reaction K-s = 0.1 s(-1) are obtained. This communication presents a multimolecular adsorption model to explain the properties of the direct electron reaction between GOx and bare silver electrodes . The residual valence force may be an important factor to ensure a di rect electron transfer reaction on the bare electrode. On the basis of the experimental fact that only biologically active GOx exhibits elec trochemical activity in solution, a facile analytical method for analy zing the active GOx concentration is developed. The results determined correspond very well to that of a spectrometric method.