A.E. Kitova, V.V. Kolesov, R.V. Mikhailova, T.V. Semashko, A.N. Reshetilov

Development of electrochemical biosensor-based domestic sensing elements which could be widely available and creation of relevant portable glucose meters which could make it possible to perform highly accurate measurement of glucose in blood with a considerable reduced total cost for the analysis are extremely topical. Glucose determination in physiological fluids is among common clinical analyses and of particular importance for diagnosis and control of diabetes mellitus and some other diseases. There exist series of methods of glucose analysis (reductometer, enzymatic, colorimetric and electrochemical analyses) widely used in clinical biochemistry. Electrochemical method is used for electrochemical registration of oxygen consumption or hydrogen peroxide formation in glucose oxidase and for the assessment of reaction intensity through transfer of electrons from active center of the enzyme to an electrode with participation of mediators of electron transfer. The first models of such devices appeared in early 1960s, by present many laboratory models of electrochemical glucose oxidase-based biosensors are developed. A mediator-based biosensor is a "second-generation" biosensor based on charge transfer from active center of the enzyme by the mediator. The working potential of the electrode used to investigate the process of electrocatalytic oxidation of substrates, is determined by redox potential (E) of mediator couple. In this work benzoquinone and potassium hexacyanoferrate (III) were chosen as mediators to create biosensors. Glucose oxidase (producers: Penicillium funiculosum 46.1 and Penicillium adametzii LF F-2044.1) was employed. Glucose oxidase immobilization requires the use of glutaraldehyde. Biocomposites were placed on the surface of electrochemical sensors and further incorporated in the composition of a microcappillary cell. These biocomposites should provide high precision of glucose determination and economic efficiency of fabrication process.