Voltammetric Studies of 3‐Nitro‐tyrosine Electro‐oxidation at Solid Electrodes and its Interaction with DNA

The electrochemical oxidation of 3‐nitro‐tyrosine (3‐NO2‐Tyr) was studied in aqueous media at metallic electrodes (platinum and gold), using voltammetric techniques. The interaction between 3‐NO2‐Tyr and double helix DNA (dsDNA) in a physiological medium was also investigated. Electro‐oxidation of 3‐NO2‐Tyr occurs in one single irreversible pH‐dependent step with the transfer of one electron and one proton from the phenolic group to the formation of radicals, which preferably dimerize, fouling the electrode surfaces. The differential pulse voltammetry and gel electrophoresis results clearly demonstrated a strong interaction of 3‐NO2‐Tyr with the dsDNA for the formation of a stable 3‐NO2‐Tyr‐dsDNA complex.