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Journal of Chemistry
Volume 2013 (2013), Article ID 946230, 7 pages
Research Article

A Voltammetric Sensor Based on NiO Nanoparticle-Modified Carbon-Paste Electrode for Determination of Cysteamine in the Presence of High Concentration of Tryptophan

1Department of Chemistry, Science and Research Branch, Islamic Azad University, Mazandaran, Iran
2Department of Physics, Sari Branch, Islamic Azad University, Sari, Iran
3Department of Chemistry, Faculty of Science, Hakim Sabzevari University, P.O. Box 397, Sabzevar, Iran

Received 25 May 2013; Accepted 8 September 2013

Academic Editor: Yehia Mechref

Copyright © 2013 Hassan Karimi-Maleh et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A carbon-paste electrode modified with ferrocenecarboxaldehyde and NiO nanoparticle (NiO/NPs) was used for the sensitive and selective voltammetric determination of cysteamine in the presence of tryptophan. The oxidation of cysteamine at the modified electrode was investigated by cyclic voltammetry (CV), chronoamperometry, and square-wave voltammetry (SWV). The values of the catalytic rate constant ( ) and diffusion coefficient ( ) for cysteamine were calculated. The modified electrode exhibits an efficient electron-mediating behavior together with well-separated oxidation peaks for cysteamine and tryptophan. At the optimum pH of 7.0 in a 0.1 M phosphate buffer solution, the SWV anodic peak currents showed a linear relationship versus cysteamine concentrations in the range of 0.09–300.0 µM and a detection limit of 0.06 µM. Finally, the proposed method was also examined as a selective, simple, and precise electrochemical sensor for the determination of cysteamine in real samples such as urine and capsule.