Surface Termination Effect of Boron-Doped Diamond on the Electrochemical Oxidation of Adenosine Phosphate

Electrochemical oxidation of adenosine phosphates, including adenosine 5'-monophosphate (AMP), adenosine 5'-diphosphate (ADP), and adenosine 5'-triphosphate (ATP), have been studied using boron-doped diamond (BDD) electrodes. Cyclic voltammograms in phosphate buffer solution pH7.4 showed a typical oxidation peak at the potential of around +1.3V (vs. Ag/AgCl) attributable to the oxidation of adenine base moiety. This peak appears at both cathodically and anodically treated BDD. However, investigation at low pH showed, whereas the oxidation peak could be well observed for the oxidation of each AMP, ADP, and ATP at cathodically treated BDD, it was only found for the oxidation of AMP at anodically-treted BDD electrodes. Linear calibration curve can be achieved in the concentration range of 20 to 200μM with an average detection limit of 2μM (S/N=3). Furthermore, cathodic treatment has demonstrated its ability to maintain the electrode surface from biofouling, resulting in the excellent stability of current responses.