Abstract: An amperometric glucose biosensor has been developed based on immobilization of GODin electrochemically synthesized poly (3, 3′-diaminobenzidine) (PDAB) film on a platinized glassy carbon electrode(PGCE).The PGCE provides a large apparent surface area ,and GOD entrapped in the of the electrodeposited platinum particles is more stable than on a platinum disc electrode surface. The sensor respeonses to β-D-glucose linearly over a concentration range of 1×10^-6to 1×10^-3mol/L, and the detection limit is 5. 1×10^-7mol/L.At a concentration of 0. 1 mmol/Lglucose, the response current of the sensor is fifty fold higher than that of the sensor prepared with a platinum disc electrode.The response time of the sensor is less than 4 s and the life time is over 6 months.Due to the permselective characteristics of the PDAB film, the effects of electroactive interferents such as ascorbic acid and uric acid, can be significantly reduced.

Key words: Biosensor, 3,3′-Diaminobenzidine, Electropolymerization, Glucose oxidase.Platinized glassy carbon electrode