The main advantage of the use of electrochemical methods is that the object studied is under conditions very close to the natural ones. Next advantage is that the same information about the sample can be received with lower costs than other methods. The electrode double layer impedance measurement is effective electrochemical method of the study of interaction of the substances on electrode surface. It is much more sensitive on adsorption processes than other electrochemical methods. After the mathematical evaluation of the results of the electrode double layer impedance measurements it was found, that the adsorption energies of xanthine are much higher than those of adenine and for hypoxanthine are close to adenine. This result could be connected with the role of these two adenine metabolites in nucleic acids. The measurements in the solutions, containing different methyl derivatives of xanthine showed that the adsorption behaviour of every substance is strongly dependent on the position of the methyl group in the molecule. From the dependence of the electrode double layer impedance on the potential and frequency in the solution containing 3'-azido-2'3'-dideoxythymidine (AZT) it was found, that under conditions studied a reduction process occurs in the sample near-IV vs. AgCl. The adsorption behaviour of AZT is the same as that of thymidine both at room temperature and at lower ones (near 0 degree C). The measurement of the electrode double layer impedance is the sensitive method for the study of the properties of the nucleic acids components that could be used in the field of new antiviral agents development.

Biofyzikální ústav AV CR Brno