Hamidreza Zare-mehrjardi
Abstract
In this study, the surface of the glassy carbon electrode (GCE) is modified with the nanocomposite of graphene oxide (GO)/ ionic liquid (1-Butyl-3-methylimidazolium tetrafluoroborate; [BMIM]BF4). The electrochemical behavior of ascorbic acid (AA) and dopamine (DA) at the surface of the modified glassy ...
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In this study, the surface of the glassy carbon electrode (GCE) is modified with the nanocomposite of graphene oxide (GO)/ ionic liquid (1-Butyl-3-methylimidazolium tetrafluoroborate; [BMIM]BF4). The electrochemical behavior of ascorbic acid (AA) and dopamine (DA) at the surface of the modified glassy carbon electrode was studied using the differential pulse and cyclic voltammetric methods (DPV and CV). The results show good response sensitivity to AA and DA. The acceleration of the electron transfer rate and enhancement of the electroactive surface area is obtained due to a synergistic effect in the concurrent presence of GO and [BMIM]BF4 at the surface of the electrode. The presence of GO caused to a higher specific surface of the electrode, and ionic liquid ([BMIM]BF4) increased the ion conductivity and dispersibility in the modifier layer at the surface of the GCE. These results obtained in optimum conditions, show good peak separation for AA and DA (more than 300 mV), and the sub-micromolar detection limits for them. The obtained results in this work, make the modified GCE very effective in the manufacture of simple devices for the detection of AA and DA in human urine samples.
Mohammad Mazloum-Ardakani; Zahra Alizadeh; Laleh Hosseinzadeh; Bibifatemeh Mirjalili; Naeimeh Salehi
Abstract
In this work, we synthesis and application of functionalized carbon nanotubes (CNTs) In this work, we synthesis and application of functionalized carbon nanotubes (CNTs) with6-amino-4-(3,4-dihydroxyphenyl)-3-methyl-1,4-dihydropyrano[2,3-c]pyrazole-5 carbonitrile (pyrazole derivative (APC)) as sensing ...
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In this work, we synthesis and application of functionalized carbon nanotubes (CNTs) In this work, we synthesis and application of functionalized carbon nanotubes (CNTs) with6-amino-4-(3,4-dihydroxyphenyl)-3-methyl-1,4-dihydropyrano[2,3-c]pyrazole-5 carbonitrile (pyrazole derivative (APC)) as sensing platform toward hydrazine (HZ). Electrochemical properties of functionalized carbon nanotubes composite (APC-CNT) were investigated by cyclic voltammetry, chronoamperometry and differential pulse voltammetry techniques. It was found that the APC-CNT composite exhibited a pair of redox peaks, which is due to the electron transfer between the APC and the glassy carbon electrode. The electrocatalytic properties of the APC-CNT composite for HZ oxidation was remarkably increased as compared to only CNTs. The kinetic parameters of the APC-CNT composite in the presence and absence of HZ was studied by electrochemical methods. The APC-CNT modified electrode revealed an excellent voltammetric response to oxidation of HZ with a wide linear range from 0.01 μM to 120.0 µM and limit of detection of 8.6 nM. Also, APC-CNT modified electrode shows high selectivity, good stability, reproducibility with a RSD less than 2.11%.
Karim Asadpour-Zeynali; Yaser Arteshi
Volume 4, Issue 1 , March 2017, , Pages 51-58
Abstract
In this research, an inexpensive and effective method for determination of Isoniazid (INH) is presented by using a poly (Eriochrome black T) modified pencil lead electrode. The potential of modified electrode in electrochemical sensing of INH was evaluated by cyclic voltammetry and hydrodynamic amperometry ...
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In this research, an inexpensive and effective method for determination of Isoniazid (INH) is presented by using a poly (Eriochrome black T) modified pencil lead electrode. The potential of modified electrode in electrochemical sensing of INH was evaluated by cyclic voltammetry and hydrodynamic amperometry methods. The overall number of electrons involved in oxidation of INH was fond 4 electrons. The calculate diffusion coefficient for INH was equal to 9.74 × 10-7 cm2/s. Calculated limit of detection for method was 66.0µM and 20.4µM applying cyclic voltammetry and hydrodynamic amperometry methods, subsequently. The ability of prepared electrode for determination of INH in real sample was evaluated by applying the proposed method to human plasma analysis and the results were compared with the standard method, presented by United State Pharmacopeia. Presented method exhibited a satisfying precision (%RSD=4.64). Also the proposed method showed a good accordance with standard method in confidence level of 95%.
Ghasem Karim-Nezhad; Sara Pashazadeh
Volume 2, Issue 2 , September 2015, , Pages 100-107
Abstract
In the present study, silver oxyfluoride modified silver electrode was employed to electrocatalytic oxidation of isoniazid. The process of oxidation and its kinetics were established by using cyclic voltammetry, chronoamperometry and amperometry techniques. The modified electrode shows a stable and linear ...
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In the present study, silver oxyfluoride modified silver electrode was employed to electrocatalytic oxidation of isoniazid. The process of oxidation and its kinetics were established by using cyclic voltammetry, chronoamperometry and amperometry techniques. The modified electrode shows a stable and linear response in the concentration range of 3×10−4 to 2.1×10−3 mol L-1 with a correlation coefficient of 0.9953. The overall number of electrons involved in the catalytic oxidation of isoniazid was found 4 electrons. The diffusion coefficient of 3.11×10−5 cm2 s-1 for isoniazid was also estimated using chronoamperometry study. It has been shown that using the silver oxyfluoride modified silver electrode, isoniazid can be determined by amperometry method with limit of detection of 3.85 µmol L–1. The method was successfully applied for analysis of isoniazid in solid pharmaceutical formulations. The results of the analysis suggest that the proposed method has promise for the routine determination of isoniazid in the products examined.