Voltammetric Behavior of DNA and Its Derivatives Using Screen Printed Carbon Electrodes and Its Possible Application in Genotoxicity Screening

Abstract

The aim of the current work was to characterize the electrochemical behavior of DNA and its derivatives using screen printed carbon electrodes (SPCEs). Differential pulse voltammetry (DPV) was carried out on guanine, adenine, 8-oxyguanine, 8-deoxygaunosine, deoxyguanosine, deoxyadenosine, adenosine-mono-phosphate, and adenosine-tri-phosphate solutions. Each species gave well defined oxidation peaks and the peak potential was characteristic of the DNA derivative. The effect of different concentrations of potassium dichromate on dsDNA was examined by DPV; three oxidation peaks were obtained which coincided with the peak potentials observed for 8-oxyguanine, guanine and adenine. This suggests that Cr6+ is likely to initially cause DNA damage by inducing double strand breaks that is followed by the breakage of the glycosidic bond between the purine and deoxyribose as well as chemical oxidation of guanine and adenine. It was shown that guanine seems to be more readily oxidized by the potassium dichromate than adenine. It is believed that this is the first report of a simple differential pulse voltammetric genotoxicity assay utilizing dsDNA in free solution.