Preparation of Glucose Oxidase Immobilized Electrode Using Electrodeposition Procedure and Its Glucose Sensor Properties

Abstract

The importance of glucose determinations for the diagnosis and effective treatment of diabetes has been well recognized. Therefore, much effort has been devoted to developing an effective sensor for the continuous estimation of glucose concentration in subcutaneous tissue [1]. Miniaturization of the sensor device is an important subject, since smaller devices are less invasive, both physically and psychologically. A finer device will excite fewer pain receptors in the skin and will cause less tissue damage and less pain. However, fabrication of finer sensor request precise technique to immobilize enzyme in a specific area. Conventional methods of enzyme immobilization are covalent attachment,cross-linking, hydrogel entrapment, electropolymerized polymer entrapment, and the combination of two or more methods. Among the variety of procedure for the immobilization of enzyme, electropolymerized polymer entrapment is interesting, since the enzyme will be immobilized just at the position where the electricity was passed. Similar to this procedure, Matsumoto et al reported that the layer of enzyme can be formed on the electrode by applying a potential of 1.3 V (vs Ag/AgCl) in the enzyme solution containing a nonionic surfactant such as Triton X-100. Since the obtained enzyme layer was not stable, they formed a electropolymerized polyphenol film in order to improve the stability, which also functioned as a permselective film to eliminate the influence of electroactive species excite in the biological fluid such as ascorbic and uric acids. In this study, glucose oxidase was immobilized using electrodeposition procedure and polymer film was formed to stabilize the enzyme film. Glucose sensor properties of the obtained electrode were investigated using in vitro and in vivo measurements. 1. N. Matsumoto, X. Chen and G. S. Wilson, Anal Chem, 74, 368 (2002).