Activation-based catalase enzyme electrode and its usage for glucose determination

In this study, a novel type amperometric biosensor, which is based on the activation of catalase enzyme by glucose, was developed and used for the sensitive determination of glucose. For the preparation of the biosensor catalase enzyme was immobilized in gelatin by using cross-linking agent glutaraldehyde and fixed on a pre-treated teflon membrane of a dissolved oxygen probe. Glucose was used as an activator for the catalase enzyme and determination of glucose is based on the assay of the differences on the catalase activity of the biosensor on the oxygenmeter in the absence and the presence of glucose in the reaction medium. The responses of the activation based catalase biosensor have a linear relation to glucose concentrations and good measurement correlation between 0.5 and 5.0 mu M with 2 min response time. In the optimization studies of the biosensor the most suitable catalase amount were found as 1324 U cm(-2) and also phosphate buffer (pH: 7.0; 50 mM) and 35 degrees C were obtained as the optimum working conditions. For the characterization studies of the biosensor some parameters such as activator and interference effects of some substances on the biosensor response, reproducibility and operational stability were performed.