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Journal of Analytical Methods in Chemistry
Volume 2012, Article ID 902184, 7 pages
Research Article

Voltammetric Determination of Homocysteine Using Multiwall Carbon Nanotube Paste Electrode in the Presence of Chlorpromazine as a Mediator

1Department of Chemisty, Qaemshahr Branch, Islamic Azad University, Qaemshahr, Iran
2Department of Applied Science, Qaemshahr Branch, Islamic Azad University, Qaemshahr, Iran
3Department of Nanotechnology, Langaroud Branch, Islamic Azad University, Langaroud, Iran
4Department of Chemistry, Science and Research Branch, Islamic Azad University, Mazandaran, Iran
5Environment Department, Research Institute of Environmental Sciences, International Center for Science, High Technology & Environmental Sciences, Kerman, Iran
6Department of Chemistry, Majlesi Branch, Islamic Azad University, Isfahan, Iran
7Department of Medical Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
8Department of Chemisty, Takestan Branch, Islamic Azad University, Takestan, Iran
9Department of Biochemistry, Falavarjan Branch, Islamic Azad University, Falavarjan, Iran
10Department of Physics, Takestan Branch, Islamic Azad University, Takestan, Iran

Received 23 November 2011; Revised 14 March 2012; Accepted 28 March 2012

Academic Editor: Maria da Conceição Branco Montenegro

Copyright © 2012 Fathali Gholami-Orimi 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.


We propose chlorpromazine (CHP) as a new mediator for the rapid, sensitive, and highly selective voltammetric determination of homocysteine (Hcy) using multiwall carbon nanotube paste electrode (MWCNTPE). The experimental results showed that the carbon nanotube paste electrode has a highly electrocatalytic activity for the oxidation of Hcy in the presence of CHP as a mediator. Cyclic voltammetry, double potential step chronoamperometry, and square wave voltammetry (SWV) are used to investigate the suitability of CHP at the surface of MWCNTPE as a mediator for the electrocatalytic oxidation of Hcy in aqueous solutions. The kinetic parameters of the system, including electron transfer coefficient, and catalytic rate constant were also determined using the electrochemical approaches. In addition, SWV was used for quantitative analysis. SWV showed wide linear dynamic range (0.1–210.0 μM Hcy) with a detection limit of 0.08 μM Hcy. Finally, this method was also examined as a selective, simple, and precise electrochemical sensor for the determination of Hcy in real samples.