• 文献标题:   A tantalum electrode coated with graphene nanowalls for simultaneous voltammetric determination of dopamine, uric acid, L-tyrosine, and hydrochlorothiazide
  • 文献类型:   Article
  • 作  者:   TIAN FY, LI HJ, LI MJ, LI CP, LEI YJ, YANG BH
  • 作者关键词:   multiple sensing, scanning electronmicroscopy, transmission electron microscopy, xray diffraction, differential pulse voltammetry, electrochemical impedance spectroscopy, electro catalysi
  • 出版物名称:   MICROCHIMICA ACTA
  • ISSN:   0026-3672 EI 1436-5073
  • 通讯作者地址:   Tianjin Univ Technol
  • 被引频次:   18
  • DOI:   10.1007/s00604-017-2154-y
  • 出版年:   2017

▎ 摘  要

The authors describe a voltammetric sensor for simultaneous determination of dopamine (DA), uric acid (UA), L-tyrosine (Tyr), and the diuretic drug hydrochlorothiazide (HCTZ). The assay is based on the use of graphene nanowalls deposited on a tantalum substrate. The nanowalls are characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, electrochemical impedance spectroscopy, and cyclic voltammetry. The nanowalls are vertically grown on the substrate by direct-current arc plasma jet chemical vapor deposition. The modified electrode is shown to enable simultaneous differential pulse voltammetric determination of DA, UA, Tyr, and HCTZ. The graphene nanowalls display a large specific surface, high conductivity, and a large number of catalytically active sites for oxidation of analytes. Simultaneous detection is performed best at a pH value of 7.0 and at peak potentials of 0.124 V (vs. SCE) for DA, 0.256 V for UA, 0.536 V for Tyr and 0.708 V for HCTZ. The respective detection limits are 0.04 mu M, 0.1 mu M, 0.6 mu M and 0.4 mu M. The results show that this graphene wall modified electrode is a promising tool for the design of sensitive, selective, and stable sensors.