Amperometric Glucose Biosensor Based on Immobilization of Glucose Oxidase in Chitosan Matrix Cross-Linked with Glutaraldehyde

A glucose biosensor was fabricated using chitosan film for the immobilization of glucose oxidase (GOX) and mediator in the following “sandwich” configuration:chitosan-ferrocene:GOX:chitosan using a carbon paste electrode as the basic electrode. To prevent loss of immobilized GOX under optimized conditions, the biosensor surface was cross-linked with glutaraldehyde (GA). Despite the multilayer configuration, the biosensor exhibited a relatively fast response (less than 10 s) and a linear response with glucose in the range of 8×10−4 to 1.7×10−2 M. The biosensor retained about 65 % of its original activity after 30 days of storage in a phosphate buffer at 4 °C. Applicability of the biosensor was demonstrated in real samples and the results obtained by this biosensor corroborate well with a classical UV spectrophotometric technique.