Simple electrochemical DNA biosensor for detection of DNA damage induced by hydroxyl radicals

A novel simple electrochemical DNA biosensor based on a glassy carbon electrode was prepared by adsorbing low molecular weight double-stranded DNA from salmon sperm onto the electrode surface as a biorecognition layer. The biosensor was used for detection of DNA damage by hydroxyl radicals. Hydroxyl radicals are well-known reactive oxygen species inducing the oxidative stress in DNA. They can attack all the molecules, including DNA, and play a major role in the DNA oxidative damage. They were generated for our purposes electrochemically on the surface of a boron-doped diamond film electrode. A complex characterization of the specific damaging event was then obtained using a combination of several electrochemical detection techniques: cyclic voltammetry, square-wave voltammetry, and electrochemical impedance spectroscopy.