Ghasem Karim-Nezhad; Sara Pashazadeh; Samira Honarmand
Abstract
In this study, a novel and convenient electrochemical sensor was fabricated by using dripping well-dispersed graphene oxide nanosheets, electropolymerization of poly glycine (p-Gly) and in situ plating of metallic copper nanoparticle film methods, successively. This sensor was further employed to investigate ...
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In this study, a novel and convenient electrochemical sensor was fabricated by using dripping well-dispersed graphene oxide nanosheets, electropolymerization of poly glycine (p-Gly) and in situ plating of metallic copper nanoparticle film methods, successively. This sensor was further employed to investigate the electrochemical behavior of hydrazine. Scanning electron microscopy and energy dispersive X-ray spectrometry were used for the characterization of the prepared film. Anodic peak potential of hydrazine oxidation at the surface of modified electrode shifts by about 150 mV toward negative values compared with that on the bare electrode. The kinetic parameters such as the electron transfer coefficient (α) and charge transfer rate constant (k) for the oxidation of hydrazine was determined utilizing cyclic voltammetry (CV). The diffusion coefficient (D) of hydrazine was also estimated using chronoamperometry. The dynamic detection range of this sensor to hydrazine was 5- 60 and 80- 150 µM at the modified electrode surface using an amperometric method. The detection limit and quantitation are 5.33 µM and 17.77 µM, respectively. A new voltammetric method for determination of hydrazine was erected and shows good sensitivity and selectivity, wider linear relationship, very easy surface update and good stability.
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.
