To determine dopamine (DA) in the presence of high concentration of ascorbic acid (AA), a glassy carbon electrode modified by ;carbon atom wires (CAWs), a kind of new homemade material, was investigated by cyclic voltammetry. It was found that the electrochemical responses of DA were affected by the presence of AA, the pH value of the electrolytic solution and an acid treated process on CAWs. The HNO3 treated CAW modified electrode exhibited excellent ability to discriminate DA from AA by means of cyclic voltammetry and the separation of their anodic peak potentials was apart as wide as 0.298 V in pH 6.00 phosphate buffer solution containing 0.50 mM DA and 5.00 mM AA at the scan rate of 50 mV/s at the modified electrode. (c) 2005 Elsevier B.V. All rights reserved.