Scientia Iranica

Scientia Iranica

New molecular self-assembled monolayers on gold electrode for simultaneous determination of epinephrine and uric acid

Authors
Mohammd Mazloum-Ardakani
Afsaneh Dehghani-Firouzabadi
Ali Benvidi
Bi-Bi Fatemeh Mirjalili
Mohammad Ali Mirhoseini
Department of Chemistry, Faculty of Science, Yazd University, Yazd, I.R.Iran
Abstract
In the present paper, we use a gold electrode modified by 2-(3, 4-dihydroxy phenyl) benzothiazole self-assembled monolayer (DHT-SAM) for the determination of epinephrine (EP) and uric acid (UA). Initially, DHT-SAM was characterized by different techniques. CV was used to investigate the redox properties of the modified electrode at various scan rates. The apparent charge transfer rate constant, ks and transfer coefficient (α) were calculated. Next, electro oxidation of epinephrine (EP) and uric acid (UA) on a gold electrode modified by a self-assembled monolayer of DHT mediated was investigated. At the optimum pH of 7.0, the oxidation of EP occurs at a potential about 200 mV less positive than that of an unmodified gold electrode. The values of transfer coefficients (α = 0.35), catalytic rate constant (k = 4.4 × 104 M-1s-1) and diffusion coefficient (D = 1.03 × 10-6cm2s-1) were calculated for EP, using electrochemical approaches. Differential pulse voltammetry (DPV) exhibited a linear dynamic range over the concentration range of 0.5–400.0 µM and a detection limit (3s) of 0.11 µM for EP in pH= 7. Finally, simultaneous determination of EP and UA at the modified electrode was described and used for the determination of EP in EP ampoule.
Keywords
Self-assembled monolayer membrane
Quartz Crystal Microbalance
Epinephrine
Uric acid
Scientia Iranica
Volume 21, Issue 6 - Serial Number 6
Transactions on Nanotechnology (F)
December 2014
Pages 2449-2458

  • Receive Date 26 November 2014
  • Accept Date 27 July 2017