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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Huang, Y., Cheng, C., Tian, X., Zheng, B., Li, Y., Yuan, H., Xiao, D., & Choi, M. (2013). Low-potential amperometric detection of dopamine based on MnO2 nanowires/chitosan modified gold electrode. Electrochimica Acta, 89, 832-839. https://doi.org/10.1016/j.electacta.2012.11.071