Detection of damage to DNA and antioxidative activity of yeast polysaccharides at the DNA-modified screen-printed electrode.

A simple procedure for the voltammetric detection of the DNA damage and antioxidants protecting DNA from its damage using a disposable electrochemical DNA biosensor is reported. The carbon-based screen-printed electrode (SPE) modified by a surface layer of the calf thymus double stranded (ds) DNA was used as a working electrode in combination with a silver/silver chloride reference electrode and a separate platinum auxiliary electrode. The [Co(phen)(3)](3+) ion served as the dsDNA redox marker and the [Cu(phen)(2)](2+) and [Fe(EDTA)](-) complex compounds were used as the DNA cleavage agents under the reduction by a chemical reductant (ascorbic acid).

Evaluation of the redox properties and anti/pro-oxidant effects of selected flavonoids by means of a DNA-based electrochemical biosensor.

Quercetin and rutin as well as catechin and epigallocatechin gallate were investigated, as widely distributed representatives of flavonols and flavanols, respectively, regarding their anti/pro-oxidant properties. The flavonoids are irreversibly oxidized at a dsDNA-modified screen-printed electrode within 0.368 to 0.