Galactose biosensors using composite polymers to prevent interferences.

A biosensor using a composite polymer to prevent interferences was used in a flow injection analysis system for the detection of galactose in human plasma. The biosensor consisted of galactose oxidase immobilized on a platinized carbon electrode that had been modified with a composite polymer. The composite polymer showed improved selectivity to hydrogen peroxide compared with either of its individual polymeric components, Nafion and a copolymer of diaminobenzene and resorcinol. The composite polymer minimized the effect of possible interference from urate, ascorbate, and acetaminophen. This analytical system had a minimum detection limit of 50 microM, linearity to 6 mM, a storage stability of greater than 30 days, and a high sample throughput (approx. 120 samples/h).