A mesoporous carbon nanofiber-modified pyrolytic graphite electrode used for the simultaneous determination of dopamine, uric acid, and ascorbic acid

A mesoporous carbon nanofiber-modified pyrolytic graphite electrode (MCNF/PGE) has been prepared and applied to the simultaneous electrochemical determination of dopamine (DA), uric acid (UA) and ascorbic acid (AA). The oxidation overpotentials of these biomolecules decrease significantly, the overlapping of these peaks in bare PGE is well resolved, and their anodic peak currents increase dramatically in MCNF/PGE due to the large amount of edge-plane-like defects, large surface area and especially the mesoporous structure of MCNFs. Using this method, anodic currents of DA, UA and AA are linear with their concentration in the range of 0.05-30 mu M, 0.5-120 mu M and 0.1-10 mu M, respectively, with detection limits of 0.02, 0.2 and 50 mu M. The good sensitivity and reproducibility of the proposed electrode make it be used as a good electrochemical sensor for the simultaneous determination of DA, UA and AA in real sample analysis. (C) 2011 Elsevier Ltd. All rights reserved.