Direct electrocatalytic and simultaneous determination of purine and pyrimidine DNA bases using novel mesoporous carbon fibers as electrocatalyst

Novel mesoporous carbon fibers (MCFs) were fabricated through a self-templating strategy and solution growth process. MCF modified glassy carbon electrode (MCF/GCE) was proposed for the direct electrocatalytic and simultaneous determination of four DNA bases (guanine (G), adenine (A), thymine (T) and cytosine (C)) using differential pulse voltammetry (DPV) measurement. The MCF/GCE exhibits satisfactory electrocatalytic activity by significantly enhancing the oxidation peak currents and lowering the oxidation potentials toward the four bases when compared with those on GCE. Especially, MCF greatly accelerates the electron transfer of pyrimidine base, which have high oxidation potentials and slow electron transfer kinetics. Moreover, MCF/GCE realizes the simultaneous determination of four DNA bases with low detection limits, high sensitivity and wide linear range. More important, the proposed electrode was successfully applied in the direct detection of bases in herring sperm DNA sample with satisfactory results. Besides, the MCF/GCE shows good long-term stability and reproducibility. These superior performances of MCF/GCE toward purine and pyrimidine DNA bases provide a good possibility for applying the MCF/GCE in our further DNA biosensor research.