ELECTRON-TRANSPORT RATES IN AN ENZYME ELECTRODE FOR GLUCOSE

We describe here the kinetics and mechanism of electron transport in an enzyme electrode where glucose oxidase is connected to the electrode surface with an electron transfer relay consisting of an osmium polypyridyl complex pendent on a polypyridine backbone. The effective electron diffusion coefficient in this polymer hydrogel was measured in films containing various loadings of enzyme using a steady-state-method involving interdigitated array electrodes and was found to range between 1.6x10(-9) and <1.5x10(-10) cm(2) s(-1). The behavior of this parameter as a function of enzyme loading was related to the mechanism proposed to be operating in these sensors.