A biosensor based on immobilization of horseradish peroxidase in chitosan matrix cross-linked with glyoxal for amperometric determination of hydrogen peroxide

An amperometric biosensor for hydrogen peroxide (H2O2) was developed via an easy and effective enzyme immobilization method with the sandwich configuration: ferrocene-chitosan: HRP: chitosan-glyoxal using a glassy carbon electrode as the basic electrode. In order to prevent the loss of immobilized HRP under optimized conditions, the biosensor surface was cross-linked with glyoxal. Ferrocene was selected and immobilized on the glassy carbon electrode surface as a mediator. The fabrication procedure was systematically optimized to improve the biosensor performance. The biosensor had a fast response of less than 10 s to H2O2, with a linear range of 3.5 x 10(-5) to 1.1 x 10(-3) M, and a detection limit of 8.0 x 10(-6) M based on S/N = 3.