Determinatiom of 8‐Hydroxy 2′‐Deoxyguanosine Using Electrodes Modified with a Dispersion of Carbon Nanotubes in Polyethylenimine

Abstract Hydroxyl radicals easily oxidize biomolecules such as proteins and DNA. The most abundant oxidative product of DNA is 8‐hydroxy 2′‐deoxyguanosine (8‐OHdG) and this is considered a biomarker of oxidative DNA damage. This work studies the electrochemical behavior of 8‐OHdG on electrodes modified with carbon nanotubes dispersed in polyethylenimine. The technique of differential pulse anodic stripping voltammetry (DPASV) enables quantification of 8‐OHdG in the presence of its major interferents, such as ascorbic acid and uric acid. We obtained linear calibration plots in the range from 5.0×10 −7 M to 3.0×10 −5 M, with detection limit ( DL ) of 1.0×10 −7 M and the quantification limit ( QL ) of 3.0×10 −7 M.