Abstract: A bienzyme glucose sensor with 1, 1' -dimethylferrocene(DMFc) as an electron transfer mediator is described. Using nafion, DMFc was coated on a glassy carbon electrode (GCE) surface, horseradish peroxidase (HRP) and glucose oxidase (GOD) were then immobilized on the DMFc/Nafion film, forming a GOD/HRP/DMFc/Nafion-modified electrode. The characteristics of the sensor can be shown by cyclic voltammetry and constant potential measurements. The sensor responded fast to glucose, the time required to reach 95 % of the steady-state current was less than 30s. The sensor displays a sensitive catalytic current response to glucose and could be operated at a potential range in which the oxidation of common interfering species,such as ascorbic acid and uric acid, does not occur. The sensor is stable for 31 days and detection limit is 2 μmol/L.

Key words: 1,1'-Dimethylferrocene, Nafion, Biosensor, Glucose