Immobilization of Glucose Oxidase in GLYMO/MTEOS Sol-Gel Film for Glucose Biosensor Application

An electrochemical biosensor was developed by using the sol-gel coating solution. The modified platinum electrode used in the study was constructed by immobilization of glucose oxidase under a layer of sol-gel film. The coating solution was prepared by using GLYMO, and MTEOS. Electrochemical measurements were carried out amperometrically by determining hydrogen peroxide produced by the enzymatic reaction between glucose and glucose oxidase. It was ob served that the amperometric response of the enzyme electrode was linear for gluco se concentrations in the range from 2 to 10 m M. The response time of the biosensor to reach a steady-state cur rent value was approximately 80 s. The glucose selectivity of the biosensor was determined in the presence of some interfering substances, such as lactose, sucrose, urea, uric acid, oxalic acid, and ascorbic acid. It was ob served that the interfering molecules did not cause any observable signal. The stability of the sensor was investigated, and it was found hat the initial sensor response decreased approximately 44% over a period of 30 days of storage in dry state at 4 degrees C.