Electrocatalytic oxidation of cysteine at carbon nanotube powder microelectrode and its detection

The electrocatalytic oxidation of cysteine at carbon nanotube (CNT) was studied. It was found that the electrochemical behaviors of cysteine were greatly improved at CNTs, indicating that the anodic oxidation could be catalyzed at CNTs. The kinetics parameters of this process were calculated, the heterogeneous electron transfer rate constant k was 0.0042 cm s(-1), (1-alpha)n(alpha) was 0.30. The carbon nanotube powder microelectrodes (CNTPMEs) were also found with higher sensitivity for cysteine detection than other common electrodes, and 2 muM sample could be determined easily, indicating that it could be used as cysteine sensors. (C) 2003 Elsevier Science B.V. All rights reserved.