AMPEROMETRIC BIOSENSOR SENSITIVE TO GLUCOSE AND LACTOSE BASED ON COIMMOBILIZATION OF FERROCENE, GLUCOSE-OXIDASE, BETA-GALACTOSIDASE AND MUTAROTASE IN BETA-CYCLODEXTRIN POLYMER

An amperometric biosensor sensitive to glucose and lactose has been de veloped by immobilizing glucose oxidase (GOD), beta-galactosidase, mut arotase and ferrocene in beta-cyclodextrin polymer. The ferrocene is i ncluded in the cavities of the beta-cyclodextrin polymer through a hos t-guest chemical reaction whereas glucose oxidase, beta-galactosidase and mutarotase are cross-linked with the beta-cyclodextrin polymer. Cy clic voltammetry and amperometric measurement have been employed for t he first time to show the efficacy of electron transfer between immobi lized glucose oxidase and a glassy carbon electrode via ferrocene incl uded in the cavities of beta-cyclodextrin polymer. Performance and cha racteristics of the biosensor were evaluated with respect to response time, detection limit, selectivity, and dependence on applied potentia l, temperature and pH as well as operating and storage stability. The stability of the enzyme membrane was greatly enhanced by cross-linking of the enzymes with beta-cyclodextrin polymer because of the water ab sorbability of the beta-cyclodextrin polymer. (C) 1998 Elsevier Scienc e B.V.