Impedance analysis of DNA and DNA-drug interactions on thin mercury film electrodes.
|Článek v odborném periodiku
|Časopis / Zdroj
|Critical Reviews in Analytical Chemistry
|Fakulta / Pracoviště MU
|electrochemical impedance spectroscopy; EIS; DNA adsorption; echinomycin; DNA-echinomycin interaction; mercury film electrodes;
|Electrochemical behaviour of echinomycin, DNA and DNA-echinomycin complex at the mercury film electrodes (MFE) was studied by measurement of the impedance of the electrode double layer (dependence of the differential capacitance C on the electrode potential, C-E curves, and dependence of the impedance Z on ferquency - electrochemical impedance spectroscopy, EIS). Mercury film was plated either on a glassy carbonelectrode (GCE) or pyrolytic graphite electrode (PGE). The capacitance measurement showed that echinomycin forms the pseudocapacitance redox peak around potential -0.53 V at the MFE.Interaction of single stranded (ss) and double stranded (ds) DNA with echinomycin at DNA-modified electrode surface was studied using EIS with adsorptive transfer method. Pseudocapacitance peak of echinomycin was observed with dsDNA-echinomycin complex, but not with ssDNA-echinomycin comlex. This result is in agreement with the known strong binding of echinomycin to dsDNA by bis-intercalation and only very weak interactin of echinomycin with ssDNA.