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Journal of Nanomaterials
Volume 2011, Article ID 464919, 6 pages
Research Article

Carbon Nanotubes/Gold Nanoparticles Composite Film for the Construction of a Novel Amperometric Choline Biosensor

1MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China
2University Hospital, South China Normal University, Guangzhou 510631, China
3School of Electronic and Information Engineering, South China University of Technology, Guangzhou 510641, China

Received 17 July 2011; Revised 26 September 2011; Accepted 3 October 2011

Academic Editor: Yanqiu Zhu

Copyright © 2011 Baoyan Wu 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.


This study develops a facile method to fabricate a novel choline biosensor based on multiwalled carbon nanotubes (MWCNTs) and gold nanoparticles (AuNPs). Chitosan, a natural biocompatible polymer, was used to solubilize MWCNTs for constructing the aqueous Chit-MWCNTs solution. Then Chit-MWCNTs were first dropped on the surface of a cleaned platinum electrode. Finally, a thiolated silica sol containing AuNPs and choline oxidase (ChOx) was immobilized on the surface of the Chit-MWCNTs-modified electrode. The MWCNTs/AuNPs/Pt electrode showed excellent electrocatalytic activity for choline. The resulting choline biosensor showed high sensitivity of choline (3.56 μA/mM), and wide linear range from 0.05 to 0.8 mM with the detection limit of 15 μM. In addition, good reproducibility and stability were obtained.