Department of Chemistry
Low-potential amperometric detection of dopamine based on MnO2 nanowires/chitosan modified gold electrode
In this research, a manganese dioxide (MnO2) nanowires/chitosan-modified gold (Au) electrode was successfully fabricated for amperometric determination of dopamine (DA) at a very low working potential (0.00 V vs. SCE). The electrochemical properties of the modified Au electrode were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The detection scheme was proposed to involve two major reactions: the chemical oxidation of DA to o-dopaminoquinone by MnO2 nanowires, and then the electro-reduction of o-dopaminoquinone to DA at a low working potential (0.00 V vs. SCE), resulting in a distinct reduction response current. The modified Au electrode displays good amperometric response to DA in a wide concentration range 0.10 μM to 1.10 mM. The fabrication of MnO2 nanowires/chitosan-modified Au electrode is simple and highly reproducible (RSD = 3.8%, n = 5). It exhibits excellent analytical performance in terms of low working potential (0.00 V vs. SCE), long shelf-life (90% of its initial response after 1-month storage) and high repeatability (RSD = 2.2%, n = 5). Finally, it was applied to determine DA in real samples directly with high accuracy (99%) and good recovery (99.7-103%), confirming its promising application in routine DA analysis. © 2012 Elsevier Ltd. All Rights Reserved.
Dopamine, Low potential, Manganese dioxide, Nanowires, Reduction
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Link to Publisher's Edition
Huang, Ying, Changming Cheng, Xianqing Tian, Baozhan Zheng, Yi Li, Hongyan Yuan, Dan Xiao, and Martin M.F. Choi. "Low-potential amperometric detection of dopamine based on MnO2 nanowires/chitosan modified gold electrode." Electrochimica Acta 89 (2013): 832-839.