title: Selective detection of dopamine in the presence of ascorbic acid by use of glassy-carbon electrodes modified with both polyaniline film and multi-walled carbon nanotubes with incorporated beta-cyclodextrin.
abstract: A simple, sensitive, and reliable method based on a combination of multi-walled carbon nanotubes with incorporated beta-cyclodextrin (beta-CD-MWNTs) and a polyaniline (PANI) film-modified glassy-carbon (GC) electrode has been successfully developed for determination of dopamine (DA) in the presence of ascorbic acid (AA). The PANI film had good anti-interference properties and long-term stability, because of the permselective and protective properties of the conducting redox polymer film. The acid-treated MWNTs with carboxylic acid functional groups promoted the electron-transfer reaction of DA and inhibited the voltammetric response of AA. Sensitive detection of DA was further improved by the preconcentration effect of formation of a supramolecular complex between beta-CD and DA. The analytical response of the beta-CD-MWNTs/PANI film to the electrochemical behavior of DA was, therefore, better than that of a MWNTs/PANI film, a PANI film, or a bare glassy-carbon (GC) electrode. Under the conditions chosen a linear calibration plot was obtained in the range 1.0 x 10(-7)-1.0 x 10(-3) mol L(-1) and the detection limit was 1.2 x 10(-8) mol L(-1). Interference from AA was effectively eliminated and the sensitivity, selectivity, stability, and reproducibility of the electrodes was excellent for determination of DA.
authors.affiliation: State Key Laboratory of Chemical, Biological Sensing Technologies and Chemometrics, Hunan University, Changsha 410082, People's Republic of China.
authors.forename: Tanji
authors.initials: T
authors.lastname: Yin
authors.forename: Wanzhi
authors.initials: W
authors.lastname: Wei
authors.forename: Jinxiang
authors.initials: J
authors.lastname: Zeng
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D001205:Ascorbic Acid / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D004298:Dopamine / Q000032:analysis* / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D013997:Time Factors; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D000814:Aniline Compounds; D037742:Nanotubes, Carbon; D047392:beta-Cyclodextrins; C416807:polyaniline; D002244:Carbon; D001205:Ascorbic Acid; D004298:Dopamine