Electrochemical Oxidation of Native Double-Stranded DNA on a Graphene-Modified Glassy Carbon Electrode

The electrochemistry of double-stranded DNA (dsDNA) was investigated on a graphene-modified glassy carbon electrode (GR/GCE). Electrochemical characterization showed that GR on GCE surface significantly enhanced the specific surface area and electrical conductivity of the sensing platform. On GR/GCE, the electrooxidation peak of guanine residues in dsDNA was obviously enhanced and the peak potential was significantly lowered as compared to bare GCE. The electrochemical parameters and influence factors for measurements were investigated. Under the optimal conditions, the peak current linearly increased with dsDNA concentrations in the range from 1 to 500 µg mL−1 with a detection limit of 0.35 µg mL−1.