Preparation and characterization of polymer based nanocomposite electrodes and their application to determination of arsenic in real samples

In recent years, sensor studies which provide information on physic, chemistry and biology were increased with the progress on nanoscience and nanotechnology. Because of the insufficient behaviour of conventional electrodes in some applications, the necessity of different active surfaces which were more selective and catalytically active towards analytes. The combination of metal nano particles with conductive polymers and graphene oxide which have high conductivity and wide active surface area were used as important new electrode materials. In the first part of this thesis which consisted of two different sections, graphene oxide was synthesized with Brodie method and it was used as working electrode. Metal nano particles, poly(p-aminophenol) and graphene oxide modified glassy carbon electrode was prepared and their effect on arsenic oxidation peak was investigated. The best catalytic activity towards arsenic oxidation reaction in 0.1M HCI solution was obtained for existence of Au nanoparticles on the polymer surface (Au/PPAP/GO/GCE). However bare glassy carbon electrode wasn't response for arsenic; Au/GO/GCE, Au/GO/PPAP/GCE and Au//PPAP/GO/GCE had good response for arsenic. Among these modified electrodes, the best current was obtained from Au/PPAP/GO/GCE. Also, using different metal nanoparticles before Au nanoparticles; Au/Cu/PPAP/GO/GCE, Au/Ni/PPAP/GO/GCE and Au/Pt/PPAP/GO/GCE were obtained. As a result, their current were not high as Au/PPAP/GO/GCE. Second part of this thesis, polycresol red (PCR) film modified electrodes were used for arsenic oxidation. The best catalytic activity towards arsenic oxidation in 0.1 M HCI solution. Au nanoparticles and polycresol red modified glassy carbon electrore used for working electrode and 10-6 M arsenic was detected. All polymer and carbon nanotube modified electrode surfaces were characterized by X-ray diffraction spectroscopy and scanning electron microscopy.