ИСТИНА

Biomolecules as recognition elements in the electrochemical biosensor analysis are widely used due to high substrate specificity, sensitivity, and the development of theoretic laws and fundamental kinetic regularities for calculating the parameters of enzymatic/affine/redox reactions proceeding on the electrode. Hemoproteins (cytochromes P450, cytochrome c), DNA, pharmaceuticals were used as recognition elements of electrochemical biosensors. Electrode/cytochromes P450 systems are analysed in terms of the mechanisms underlying P450-catalyzed reactions. Electrochemical parameters were used for calculations of kinetic constants of enzymatic processes and electrode kinetics of electrons transfer. Bioelectrocatalysis-based screening of potential substrates or inhibitors of P450 enzymes, the stoichiometry of the electrocatalytic cycle, znd oxidation-reduction (redox) thermodynamics are described. Based on the analysis of electrocatalytic activity of various isoforms of P450 cytochromes (2B4, 1A2, 3A4, 51b1, 11A1 (P450 scc), 17A1, BM3, 260A1, 109C1, 109C2 and 109D1) developed a method of pharmacokinetic therapeutic drug monitoring. The method of the analysis of electrochemical activity of proteins and peptides based on registration of electrooxidation of amino acids and a technique of amino acid substitutions, modifications and formation of functionally significant complexes is developed. Direct redox activity of different proteins was investigated on the surface of carbon screen-printed electrodes (SPE). Modification of electrode surface is important step in biosensor preparation. Highly stable fine dispersions of MWCNTs in aqueous solutions of polyionic liquids PILs (MWCNT/PIL) were used for dsDNA assay as apoptosis marker. The linear ranges for the determination of dsDNA correspond to 5-500 μg/mL (for G) and 0.5-50 μg/mL (for A). We demonstrate that the developed MWCNT/PIL constructs are able to sense a point mutation in the 12-bases single-stranded DNA fragments. Such detection is of high clinical significance in choosing an adequate anticancer treatment, where the electrochemical idetification of the point mutation could offer time and cost benefits. (Id-190, p.66)