CHEMILUMINESCENT FLOW-INJECTION ANALYSIS OF GLUCOSE IN DRINKS WITH A BIENZYME FIBEROPTIC BIOSENSOR

A fiberoptic sensor for the chemiluminescent flow injection analysis of glucose in a one-step procedure was developed. Glucose oxidase and peroxidase were coimmobilized on a preactivated polyamide membrane. Hydrogen peroxide, generated by the glucose oxidase reaction in the presence of glucose, was detected by the chemiluminescence reaction of luminol catalyzed by peroxidase. The detection limit for hydrogen peroxide was 2.5 pmol at pH 8.5 and 0.25 pmol at pH 9.0. For 10 replicates of 0.1 nmol H2O2, the coefficient of variation was 2.5%. For glucose analysis, the detection limit was 0.25 nmol and the coefficient of variation was 3.8% for seven measurements of 2.5 nmol glucose. The method was applied for glucose analysis in soft drinks, and the results were in good agreement with the analysis by a standard spectrophotometric method. The analytical throughput was 40 samples per hour for hydrogen peroxide and 25 samples per hour for glucose.