Electrochemical behavior of gallic acid interaction with DNA and detection of damage to DNA

Electrochemical behavior of gallic acid (GA) and interaction with calf thymus DNA were explored with cyclic voltammetry and differential pulse voltammetry (DPV) in acetate buffer solution using a glassy carbon electrode (GCE) and a DNA modified GCE (DNA/GCE), respectively. A pair of redox peaks of GA appeared in the range of −0.05 ∼ +0.55 V. The anodic peak potential (Epa) was at +0.329 V and the cathodic peak potential (Epc) was at +0.211 V. The oxidation peak potential of GA was dependent on pH of solution. With adding DNA into GA solution, the peak current value of GA decreased gradually, and the peak potential shifted positively. The electrochemical parameters (diffusion coefficient D, electron transfer coefficient α, and standard rate constant ks) of free GA and binding compounds were obtained. The peak current of GA increased with the time of DNA/GCE being immersed in the GA solution. The results showed that GA could interact with DNA molecule by intercalation mode. The GA could mediate the double stranded DNA (ds-DNA) in situ damage, which was directly detected according to the anodic signal of the DNA purine bases with DPV.