Improved Electrochemical Detection of Purine Nucleobases at Mechanically Roughened Edge‐Plane Pyrolytic Graphite Electrode

Mechanically grinded edge‐plane pyrolytic graphite electrode (g‐PGEe) was applied in voltammetric analysis of purine nucleobases, acid‐hydrolyzed synthetic oligodeoxynucleotides and a nonhydrolyzed plasmid DNA. Properties of the mechanically grinded electrodes in these analytical applications were compared with some other carbon electrode types. We show that the electrode surface grinding with 15‐μm SiC particles resulted in a remarkable improvement of oxidation signals of purine bases with no addition of copper ions. Addition of the copper ions, causing a strong enhancement of the purine oxidation responses at fine‐polished carbon electrodes, had only small effect on the purine signals at the g‐PGEe. On the other hand, the g‐PGEe appeared less suitable for the ex situ AdTS voltammetric measurements of nonhydrolyzed plasmid DNA, compared to freshly peeled basal plane pyrolytic graphite electrode.