Electrochemical impedance spectroscopy of polynucleotides.
|Year of publication||2001|
|Type||Article in Proceedings|
|Conference||Book of Abstracts, XVI th International Symposium on Bioelectrochemistry and Bioenergetics|
|MU Faculty or unit|
|Keywords||electrochemical impedance spectroscopy; EIS; DNA adsorption; polyadenylic acid adsorption; poly a adsorption;; differential capacitance of the electrode double layer;|
|Description||The dependence of the impedance of the electrode double layer of mercury electrode on frequency around the potentials of the tensammetric peaks of single-stranded and double-helical polynucleotides and DNA was studied. From the frequency dependence of the impedance of the electrode double layer represented in a complex impedance plot (the imaginary component Z'' is plotted against the real component Z', Cole-Cole or Nyquist plot) the electric equivalent circuit of the electrode covered with adsorbed DNA layer was determined. It was concluded the desorption of denatured ssDNA is accompanied by higher dielectric losses than the desorption of native dsDNA. This can be explained by the higher flexibility of ssDNA compared to the dsDNA. The capacitance peak of single stranded poly A observed at pH 8 around -1.3 V splits at low frequencies in two peaks.|