Microchimica Acta

, Volume 154, Issue 1, pp 115–121

Simultaneous Determination of Dopamine and Ascorbic Acid at a Triazole Self-Assembled Monolayer-Modified Gold Electrode

Original Paper

DOI: 10.1007/s00604-006-0485-1

Cite this article as:
Yixin, S. & Fu Wang, S. Microchim Acta (2006) 154: 115. doi:10.1007/s00604-006-0485-1

Abstract.

A 3-amino-5-mercapto-1,2,4-triazole (TA) self-assembled monolayer-modified gold electrode (TA SAM/Au) is characterized by X-ray photoelectron spectroscopy, A.C. impedance, cyclic voltammetry, chronoamperometry and chronocoulometry. The TA SAM/Au exhibited good promotion of the electrochemical oxidation of dopamine. Some electrochemical parameters of dopamine such as electron transfer number, exchange current density, standard heterogeneous rate constant, diffusion coefficient, etc., were measured by different electrochemical methods. The peak currents of dopamine were linearly dependent on its concentration in the range of 1.5 × 10−6–1.0 × 10−4 mol L−1, with a detection limit of 5.0 × 10−7 mol L−1. The oxidative peak potentials of dopamine and ascorbic acid were well separated at about 190 ± 10 mV in pH 2.0 BR buffers at TA SAM/Au, the oxidation peak current increases approximately linearly with increasing concentration of both dopamine and ascorbic acid in the concentration range of 9.98 × 10−6–4.54 × 10−4 mol L−1. It can be used for simultaneous determination of dopamine and ascorbic acid.

Key words: Triazole; SAM; dopamine; ascorbic acid; simultaneous determination.

Copyright information

© Springer-Verlag/Wien 2006

Authors and Affiliations

  1. 1.Faculty of Chemistry and Material Science, Hubei UniversityWuhanChina
  2. 2.School of Engineering, Zhejiang Forestry UniversityHangzhouChina