DETERMINATION OF OXIDASE ENZYME SUBSTRATES USING CROSS-FLOW IN THIN-LAYER AMPEROMETRY

Thin-layer cross-flow amperometric detectors with enzyme modified work ing electrodes were developed for the determination of oxidase substra tes in flowing streams. The enzyme was covalently immobilized in an os mium redux polymer film on the electrode surface. Electrodes modified with glucose oxidase or lactate oxidase were prepared for the continuo us monitoring of glucose or lactate. A peroxidase electrode coupled wi th oxidase enzyme reactors was also explored for the determination of glucose, lactate, and acetylcholine/choline in continuous monitoring s ystems or following liquid chromatography. The effects of interference s, oxygen, mass transfer limiting membrane, and perfusate composition on electrode performance an discussed.