title: Fluorometric sensors based on chemically modified enzymes Glucose determination in drinks.
abstract: In this paper an enzymatic fluorometric sensor for glucose determination in drinks is presented. The sensor film was obtained by immobilisation of glucose oxidase chemically modified with a fluorescein derivative (GOx-FS) in a polyacrylamide polymer. During the enzymatic reaction the changes in the fluorescence intensity of the GOx-FS are related to the glucose concentration. Working in FIA mode, the optimum conditions found were: 0.7 ml min(-1) flow rate, 300 mul sample injection and pH 6.5. The sensor responds to glucose concentrations ranging from 400 to 2000 mg l(-1), the reproducibility is around 3% and the life-time is at least 3 months (more than 350 measurements). The sensor was applied to direct glucose determination in drinks with good accuracy; interference caused by the filter effect was avoided by the kinetics of the reaction.
authors.affiliation: Analytical Spectroscopy and Sensors Group (GEAS), Analytical Chemistry Department, Science Faculty, University of Zaragoza, 50009 Zaragoza, Spain.
authors.forename: Vanesa
authors.initials: V
authors.lastname: Sanz
authors.forename: Javier
authors.initials: J
authors.lastname: Galban
authors.forename: Susana
authors.initials: S
authors.lastname: de Marcos
authors.forename: Juan R
authors.initials: JR
authors.lastname: Castillo