Electron transfer between galactose oxidase and an electrode via a redox polymer network

Galactose oxidase from Dactyllium dendroides was purified and immobilised on a carbon electrode in a redox polymer network of a polyvinylpyridine, partially N-complexed with osmiumbis(bipyridine)chloride (POsEA). The current density of the electrodes depended on the concentration of phosphate elution buffer. By additional crosslinking with a 1% glutaraldehyde solution in 50 mM phosphate buffer, pH 7.0, an electrode with an initial current density of 0.8 mA/cm super(2) was obtained. Operational half life times were in the order of 1.2 h. The affinity of the immobilized enzyme for galactose, lactose, raffinose, glycerol and dihydroxyaceton was higher than described in literature for the enzyme in solution. Optimal temperature for the enzyme electrode was 30 degree C. The pH optimum for the immobilized enzyme was higher than for the enzyme in solution.