Ali Osman SOLAK

Article | 2014 | Journal of The Electrochemical Society161 ( 10 )

A new electrode was prepared by the electrooxidation of orto-, meta-, and para-substituted nitro phenols on glassy carbon electrode. Electrochemical modification of the electrodes was carried out in 0.01 M HCl using cyclic voltammetry (CV). Then nitro groups in the covalently grafted nitro phenol derivatives on GC electrode were reduced to amine groups in 0.01 M HCl. The electrochemical behavior of the modified electrodes was studied in the presence of electroactive redox probes such as ferrocene and ferricyanide by CV and electrochemical impedance spectroscopy (EIS). X-ray photoelectron spectroscopy (XPS) was employed to characteri . . .ze the surface structure and composition of the modified substrates. Thickness of the films was measured by using an ellipsometer. Surface topography of the nanofilms and bare GC was characterized via AFM. Graphene oxide (GO) was covalently attached on 4-aminophenyl involved surface through EDC. Simple immersing of the GO covered nanoplatform into a sample solution led to the chemical deposition by means of the interaction with Cd2+ and Pb2+ ions, simultaneously. Various analysis parameters that affect the simultaneous analysis of the ions such as deposition time, pH factor and deposition temperature, were optimized. Calibration curve for the GO grafted electrode surface with Square-wave anodic stripping voltammetry (SWASV) were obtained in the concentration range between 1 × 10−8 M and 1 × 10−12 M for Pb2+ and Cd2+. The detection limits of the modified electrode for Pb2+ and Cd2+ ions were determined to be about 3.2 (± 0.1) × 10−13 M and 2.4 (± 0.2) × 10−13 M, respectively More less

Ali Osman SOLAK

Article | 2013 | Journal of The Electrochemical Society160 ( 8 )

A nanostructured silver-aniline modified pencil electrode obtained by applying experimental design and optimization was developed for the differential pulse stripping voltammetric quantification of acetaminophen in the pharmaceutical products, tablet and syrup. The electrode development process was performed by the modification of PGE with aniline using CV procedure and the reduction of silver nanoparticle on the polyaniline modified PGE. As a result, a new electrode system consisting of a nanostructured silver-polyaniline modified pencil graphite electrode (AgNS-PA-PGE) was obtained to reach a well-defined and higher peak current f . . .or the analysis of the related drug. The calibration curve was found linear in the range of 5 × 10−8–8 × 10−7 M for acetaminophen. The validity and applicability of the proposed voltammetric method was tested by analyzing independent validation samples. It was observed that the proposed voltammetric approach for the real tablet and syrup samples gave successful analysis results More less