Nicolae Totir

Bio: Nicolae Totir is an academic researcher. The author has contributed to research in topics: Prussian blue & Conductive polymer. The author has an hindex of 4, co-authored 8 publications receiving 183 citations.

The optimization of the electrochemical preparation of Pedot-Prussian blue hybrid electrode material and application in electrochemical sensors

Abstract: The electrochemical preparation, characterization and analytical applications of a hybrid material consisting of poly(3,4-ethylenedioxythiophene) (PEDOT) conducting polymer and Prussian Blue (PB; iron(III) hexacyanoferrate(II)) are presented. The hybrid material was prepared by a two-steps method. In a first step, the organic conducting polymer coating was deposited onto platinum electrode surface from an aqueous solution containing the monomer and ferricyanide ions. In the second step, the resulted modified electrode Pt|PEDOT- FeCN was immersed in an aqueous solution containing Fe 3+ ions and the electrode potential was cycled between 0.6 and –0.4 V. The in situ formation of PB inside the PEDOT matrix has been demonstrated using cyclic voltammetry and electrochemical quartz crystal microbalance. The hybrid material maintains the electrochemical features of each component, i.e. organic and inorganic components. The inorganic component showed electrochemical activity only for the Prussian blue/Everitt’s salt redox system. The hybrid material displayed electrocatalytic activity towards dopamine oxidation in the presence of a large excess of ascorbic acid.

Electrochemical behaviour of ascorbic acid on Prussian blue modified electrodes

Abstract: Prussian Blue (PB) modified electrodes were prepared from a ferric-ferricyanide solution using potentiostatic and galvanostatic methods onto platinum and indium tin oxide (ITO) electrode surfaces. Preparation and characterisation of PB modified electrodes were carried out in acidic solutions. The amount of PB deposited onto the electrode surface can be controlled by changing the current density, the electrode potential and the time of electrolysis. The deposition efficiency and the thickness of the modifier were determined from chronoamperometric curves and cyclic voltammograms. A spectroelectrochemical study shows the variation of the absorbancies of PB deposited on ITO electrode at different electrode potentials. The electrocatalytic activity of PB was also demonstrated by the electrooxidation of ascorbic acid in acidic solution, which is a slow process on the bearing platinum electrode. A linear response was obtained up to 4.5 mM ascorbic acid.

Spectroelectrochemical studies regarding reduction of oxygen on modified electrodes with derivative porphyrins

Abstract: The mechanism of the dioxygen reduction on carbon and silver supporting electrodes modified with Ruthenium-(tetramethoxyphenyl) porphyrin was investigated by UV-vis, FTIR and Raman spectroscopy. Spectroelectrochemical results show a two-electron pathway resulting in hydrogen peroxide as primary reduction product.

Polypyrrole-based conducting polymers and interactions with biological tissues.

Abstract: Polypyrrole (PPy) is a conjugated polymer that displays particular electronic properties including conductivity. In biomedical applications, it is usually electrochemically generated with the incorporation of any anionic species including also negatively charged biological macromolecules such as proteins and polysaccharides to give composite materials. In biomedical research, it has mainly been assessed for its role as a reporting interface in biosensors. However, there is an increasing literature on the application of PPy as a potentially electrically addressable tissue/cell support substrate. Here, we review studies that have considered such PPy based conducting polymers in direct contact with biological tissues and conclude that due to its versatile functional properties, it could contribute to a new generation of biomaterials.

New trends in the electrochemical sensing of dopamine.

Abstract: Since the early 70s electrochemistry has been used as a powerful analytical technique for monitoring electroactive species in living organisms. In particular, after extremely rapid evolution of new micro and nanotechnology it has been established as an invaluable technique ranging from experiments in vivo to measurement of exocytosis during communication between cells under in vitro conditions. This review highlights recent advances in the development of electrochemical sensors for selective sensing of one of the most important neurotransmitters—dopamine. Dopamine is an electroactive catecholamine neurotransmitter, abundant in the mammalian central nervous system, affecting both cognitive and behavioral functions of living organisms. We have not attempted to cover a large time-span nor to be comprehensive in presenting the vast literature devoted to electrochemical dopamine sensing. Instead, we have focused on the last five years, describing recent progress as well as showing some problems and directions for future development.

Reduced Graphene Oxide/Copper Nanowire Hybrid Films as High-Performance Transparent Electrodes

Abstract: Hybrid films composed of reduced graphene oxide (RG-O) and Cu nanowires (NWs) were prepared. Compared to Cu NW films, the RG-O/Cu NW hybrid films have improved electrical conductivity, oxidation resistance, substrate adhesion, and stability in harsh environments. The RG-O/Cu NW films were used as transparent electrodes in Prussian blue (PB)-based electrochromic devices where they performed significantly better than pure Cu NW films.