title: Selective response of dopamine in the presence of ascorbic acid at multi-walled carbon nanotube modified gold electrode.
abstract: The acid-treated multi-walled carbon nanotubes (MWNTs), which were modified on the surface of gold electrode, offers substantial improvements in voltammetric sensitivity and selectivity towards the determination of dopamine (DA). It can inhibit the voltammetric response of ascorbic acid (AA) while the redox reaction of dopamine is promoted. When a differential pulse voltammetric (DPV) technique was used, the peak separation between DAs and AAs was 244 mV. Based on this, a selective method could be constructed to detect DA in the presence of 1,000 times higher concentration of AA. The effect of various experimental parameters on the voltammetric response of dopamine was investigated. Under the chosen conditions, the peak currents are correspondent linearly to the concentrations of DA in the range of 5 x 10(-7) approximately 4 x 10(-4) mol L(-1) with a limit of detection of 2 x 10(-7) mol L(-1). The proposed method can be applied to detect DA in real samples.
authors.affiliation: School of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, P. R. China.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
authors.forename: Fang-Hui
authors.initials: FH
authors.lastname: Wu
authors.forename: Guang-Chao
authors.initials: GC
authors.lastname: Zhao
authors.forename: Xian-Wen
authors.initials: XW
authors.lastname: Wei
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry*; D004298:Dopamine / Q000032:analysis*; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D036103:Nanotechnology; D012680:Sensitivity and Specificity
chemical_list: D006046:Gold; D001205:Ascorbic Acid; D004298:Dopamine