Voltammetric Detection of Damage to DNA by Arsenic Compounds at a DNA Biosensor

DNA biosensor can serve as a powerfull tool for simple in vitro tests of chemical toxicity. In this paper, damage to DNA attached to the surface of screen-printed carbon electrode by arsenic compounds in solution is described. Using the Co(III) complex with 1,10-phenanthroline, [Co(phen)3], as an electrochemical DNA marker and the Ru(II) complex with bipyridyne, [Ru(bipy)3], as a DNA oxidation catalyst, the portion of original dsDNA which survives an incubation of the biosensor in the cleavage medium was evaluated. The model cleavage mixture was composed of an arsenic compound at 10 mol/L concentration corresponding to real contaminated water, 2x10 mol/L Fe(II) or Cu(II) ions as the redox catalyst, and 1.5x10 mol/L hydrogen peroxide. DNA damage by arsenite, dimethylarsinic acid as the metabolic product of inorganic arsenic and widely used herbicide, as well as phenylarsonic acid and p-arsanilic acid as the representatives of feed additives was found in difference to arsenate.