A simplified enzyme-based fiber optic sensor for hydrogen peroxide and oxidase substrates

A simplified enzyme-based fiber optic sensor system has been developed for selective determination of hydrogen peroxide. Horseradish peroxidase (HRP) is immobilized on bovine albumin matrix with glutaraldehyde. A new fluorimetric substrate, thiamine is used to indicate the sensing process. Under optimized condition the measuring range of sensor is up to 1 x 10(-4)M hydrogen peroxide with a limit of detection of 5 x 10(-7)M in a 5 min response period. It can be easily incorporated in multienzyme sensors for biochemical substances which produce hydrogen peroxide under catalytic oxidation by their oxidase. This possibility has been tested for the determination of uric acid, D-amino acid, L-amino acid, glucose cholesterol, choline and acetylcholine, respectively, using a membrane with co-immobilized oxidase and horseradish peroxidase.