Analytical chemistry
Roghiyeh Pourghobadi; Mohammad Reza Baezzat
Abstract
The present study examines a new dopamine sensor based on Alumina nanoparticles modified carbon paste electrode (Al2O3NPsCPE). Moreover, the present study focuses on the electrochemical act of the Al2O3NPsCPE for the detection of dopamine by cyclic voltammetry (CV) and differential pulse voltammetry ...
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The present study examines a new dopamine sensor based on Alumina nanoparticles modified carbon paste electrode (Al2O3NPsCPE). Moreover, the present study focuses on the electrochemical act of the Al2O3NPsCPE for the detection of dopamine by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). There is also a focus on the specification of the prepared modified electrode by electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM), and there is a discussion on the influence of some experimental variables such as carbon paste composition, laboring solution pH, scan rate and possible interferences. The present study obtained a well-defined redox peak of dopamine (DA) on the Nano- Alumina/CPE at Epa=173mV and Epc=112mV, respectively. The obtained response of the sensor was linear under the optimal conditions of the catalytic peak current, in the range of 8.0-330.0 µM, and the detection limit was 2.1 µM (S/N=3) for dopamine. The proposed sensor exhibited a high sensitivity, an excellent reproducibility, good selectivity, and it was successfully used in the determination of dopamine injection samples.
Analytical chemistry
Sohrab Ershad; Noshin Safarzadeh; Hamzeh Akhondi-Yamchi
Volume 4, Issue 3, pp. 236-358, Serial No. 12 , July 2016, , Pages 256-264
Abstract
A novel chemically modified electrode containing Prussian blue complex was achieved on the surface of glass carbon electrode by sol-gel technique. The electrochemical behavior of modified electrode was characterized by cyclic voltammetry in detail. The film electrode obtained was very stable and exhibited ...
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A novel chemically modified electrode containing Prussian blue complex was achieved on the surface of glass carbon electrode by sol-gel technique. The electrochemical behavior of modified electrode was characterized by cyclic voltammetry in detail. The film electrode obtained was very stable and exhibited electrocatalytic response for oxidation of nitrite. Results showed at bare GC electrode, a small oxidation peak current was observed at about 740 mV and a well-formed sharp catalytic oxidation peak at about 600 mV was observed at Prussian blue complex modified electrode. The transfer coefficient (α) for electrocatalytic oxidation of nitrite and the diffusion coefficient of this substance under the experimental conditions were also investigated.
Physical chemistry
Reza Samimi Shalamzari; Simin Mansouri; Akram Eghbali
Volume 3, Issue 4, pp. 283-387, Serial No. 9 , October 2015, , Pages 348-355
Abstract
The conditional formal potential, E°′of Methyldopa has been studied by cyclic voltammetry at the surface of activated glassy carbon electrode (AGCE) as the working electrode in different pH phosphate buffered solutions. The experimental Standard redox potential, E°′, of Methyldopa ...
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The conditional formal potential, E°′of Methyldopa has been studied by cyclic voltammetry at the surface of activated glassy carbon electrode (AGCE) as the working electrode in different pH phosphate buffered solutions. The experimental Standard redox potential, E°′, of Methyldopa is obtained to be 0.72 mV versus SHE (Standard Hydrogen Electrode). E°′ values have also been calculated with the aid of density functional theory (DFT) method at B3LYP/6-311G Basis set in conjunction with a Polarizable Continuum Model (PCM). Innovative application of both Direct and indirect methods resulted in theoretical standard electrode potentials of the studied Methyldopa in the order of 0.68 and 0.74 mV, respectively. These results were found to be in excellent agreement with the experimental value in the order of 0.72 mV.