An optical glucose biosensor based on derived glucose oxidase immobilised onto a sol-gel matrix

Glucose oxidase, firstly covalently bonded to a fluorescein derivative, is immobilised onto a sol-gel matrix. During the enzymatic reaction, glucose reacts with the labelled enzyme and when the oxygen dissolved in the solution is consumed, an increase in the fluorescence intensity of the labelled enzyme is observed. The time at which the variation in the fluorescence intensity is observed is directly related to the glucose concentration, and it was therefore used as the analytical parameter for glucose quantification. The protocol of sol-gel formation is also optimised. The sol-gel presents a dynamic response range from 100 to 1000 mg/l with a lifetime of 15 days. (C) 1999 Elsevier Science S.A. All rights reserved.