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 immobilizati on of glucose oxidase (GOX) and mediator in the following "sandwich" config uration: chitosan-ferrocene: GOX:chitosan using a carbon paste electrode as the basic electrode. To prevent loss of immobilized GOX under optimized co nditions, 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 ra nge of 8 x 10(-4) to 1.7 x 10(-2) M. The biosensor retained about 65 % of i ts original activity after 30 days of storage in a phosphate buffer at 4 de greesC. Applicability of the biosensor was demonstrated in real samples and the results obtained by this biosensor corroborate well with a classical U V spectrophotometric technique.