Enzyme immobilization on ultramicroelectrodes through electropolymerization: Effect of polymeric film thickness on teh amperometric response of the electrode

The rapid growth in the science and technology of the biosensors demands improved methods of enzyme immobilization and miniaturization of sensor devices. The formation, on electrode surfaces, of enzyme-entrapped polymer films through electropolymerization from monomer solutions containing the enzyme offers an elegant and reliable approach for enzyme immobilization, especially on ultramicroelectrodes. Platinum ultramicrodiscelectrodes (UMDE) were fabricated in-house and immobilized with glucose oxidase (GOx) enzyme through electropolymerized films of polypyrrole and poly(I,3-diaminobenzene). The UMDE, modified with GOx-trapped polymer film was tested for its amperometric response to glucose in solution. The polymer film thickness was varied from about 10 to 466 nm by controlling the charge required for the electropolymerization and the influence of the polymer film thickness on the amperometric response to glucose was investigated. Moreover, the effect of oxygenation and de-oxygenation of the test solutions on the amperometric response was also examined. The results of the above studies are presented and discussed in this communication