The Experts below are selected from a list of 15129 Experts worldwide ranked by ideXlab platform
Alex Fragoso - One of the best experts on this subject based on the ideXlab platform.
-
A wide-range solid state potentiometric pH sensor based on poly-dopamine coated carbon nano-onion Electrodes
Sensors and Actuators B: Chemical, 2018Co-Authors: Julio C. Zuaznabar-gardona, Alex FragosoAbstract:A novel potentiometric pH sensor based on polydopamine films coated on a carbon nano-onion conductive surface is introduced. Glassy carbon Electrodes containing a carbon nano-onion layer were modified by electropolymerization and self-polymerization of dopamine. The modified surfaces were characterized by ESEM, RAMAN spectroscopy and cyclic voltammetry. The modified Electrodes displayed an almost Nernstian potentiometric response over the pH range 2–10. Furthermore, the pH sensors exhibit a fast and reversible behavior toward variations of pH and negligible interference effects from monovalent cations. The sensors showed an excellent correspondence between the pH values obtained using the GCE/CNO/PDA Electrodes and those measured with Glass Electrodes and were applied to the analysis of real samples covering a wide pH range from 2.2 to 8.3. The analytical performance is comparable to other reported devices based on electropolymerized amines over graphite and noble metal Electrodes. Their reproducible and stable response and their ease of fabrication is very promising for the miniaturization and integration of pH sensors in (bio)analytical devices.
Susan M. Fleetwood-walker - One of the best experts on this subject based on the ideXlab platform.
-
The glycine site of the NMDA receptor contributes to neurokinin1 receptor agonist facilitation of NMDA receptor agonist-evoked activity in rat dorsal horn neurons.
Brain research, 1997Co-Authors: P.a. Heppenstall, Susan M. Fleetwood-walkerAbstract:We have investigated the role of the glycine recognition site of the N-methyl-D-aspartate receptor (the GlyNMDA site) in the facilitation of NMDA receptor agonist-evoked activity in rat dorsal horn neurons that is brought about by neurokinin1 (NK1) receptor agonist and the contribution of protein kinase C (PKC) activation to this phenomenon. Ionophoresis of the selective NMDA receptor agonist 1-aminocyclobutane-cis-1,3-dicarboxylic acid (ACBD) produced a sustained increase in the firing rate of single laminae III-V neurons recorded extracellularly using multibarrelled Glass Electrodes. The highly selective NK1 receptor agonist acetyl-[Arg6,Sar9,Met(O2)11]-SP6-11 (Sar9-SP) greatly facilitated this response, but under the present conditions had no effect when applied alone or with alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor agonist) at the same current. In the presence of the GLyNMDA site antagonists 2-carboxy-4,6-dichloro-(1H)-indole-3-propanoic acid (MDL 29951), 7-chloro-3-(cyclopropylcarbonyl)-4-hydroxy-2(1H)-quinoline (L701,252), 5,7-dinitroquinaxoline-2,3-dione (MNQX) or 7-chlorothiokynurenic acid (7-CTK), or the PKC inhibitors, chelerythrine or GF109203X, the Sar9-SP-induced facilitation of ACBD-evoked activity was prevented, generally restoring activity to a level similar to that in the presence of ACBD alone, whilst an AMPA receptor antagonist, 6-nitro-7-sulfamoylbenzo(f)quinoxaline-2,3-dione (NBQX) did not inhibit the facilitation. At the same ionophoretic currents these compounds had no effect on ACBD-evoked activity in the absence of Sar9-SP but were inhibitory at significantly greater currents. To further substantiate the importance of the GlyNMDA site in the interaction, the effects of NMDA receptor antagonists selective for alternative recognition sites on the NMDA receptor were investigated. MK-801, a non-competitive NMDA receptor antagonist and arcaine, a competitive inhibitor at the polyamine site, were applied to the facilitated activity seen in the presence of Sar9-SP and ACBD, and to ACBD-evoked activity alone. Unlike the GlyNMDA site antagonists and PKC inhibitors, these compounds reduced both facilitated and ACBD-evoked activity at similar currents. Furthermore, like the NK1 receptor agonist, a selective GlyNMDA site agonist 1-aminocyclopropane carboxylic acid (ACPC) caused facilitation of ACBD-evoked activity which was also blocked by currents of L701,252 that did not alter activity evoked by ACBD alone. These data suggest that activation of the GlyNMDA site (perhaps as a consequence of glycine release or modification of its influence by intracellular signalling cascades) is an essential component of the means by which NK1 receptor activation results in facilitated responsiveness of dorsal horn neurons towards NMDA receptor agonists.
N S Sariciftci - One of the best experts on this subject based on the ideXlab platform.
-
electrocatalytic reduction of carbon dioxide using sol gel processed copper indium sulfide cis immobilized on ito coated Glass electrode
Electrocatalysis, 2015Co-Authors: Getachew Adam, Engelbert Portenkirchner, Ferhat Aslan, Philipp Stadler, Markus C Scharber, N S SariciftciAbstract:Sol-gel processed copper indium sulfide (CIS) films have been processed on Glass and transparent indium doped tin oxide (ITO)-coated Glass Electrodes by a straightforward layer by layer spin coating route yielding excellent film qualities with subsequent thermal annealing. Resulting films were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-vis spectroscopy. We apply these films in an electrochemical cell as a working electrode and take a view on the reduction of carbon dioxide (CO2) to its energy richer carbon monoxide (CO) in acetonitrile solution containing 0.1 M (C4H9)4NPF6 supporting electrolyte saturated with CO2. CIS films exhibit pronounced electrochemical and photoelectrochemical activities. Concomitantly, we quantify the generation of CO, which starts to evolve at a threshold potential of −0.60 V vs normal hydrogen electrode (NHE). The calculated faradaic efficiency of the electrochemical reduction of CO2 into CO exceeds 20 (±1) % in an optimized thin-film structure.
Ferhat Aslan - One of the best experts on this subject based on the ideXlab platform.
-
electrocatalytic reduction of carbon dioxide using sol gel processed copper indium sulfide cis immobilized on ito coated Glass electrode
Electrocatalysis, 2015Co-Authors: Getachew Adam, Engelbert Portenkirchner, Ferhat Aslan, Philipp Stadler, Markus C Scharber, N S SariciftciAbstract:Sol-gel processed copper indium sulfide (CIS) films have been processed on Glass and transparent indium doped tin oxide (ITO)-coated Glass Electrodes by a straightforward layer by layer spin coating route yielding excellent film qualities with subsequent thermal annealing. Resulting films were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-vis spectroscopy. We apply these films in an electrochemical cell as a working electrode and take a view on the reduction of carbon dioxide (CO2) to its energy richer carbon monoxide (CO) in acetonitrile solution containing 0.1 M (C4H9)4NPF6 supporting electrolyte saturated with CO2. CIS films exhibit pronounced electrochemical and photoelectrochemical activities. Concomitantly, we quantify the generation of CO, which starts to evolve at a threshold potential of −0.60 V vs normal hydrogen electrode (NHE). The calculated faradaic efficiency of the electrochemical reduction of CO2 into CO exceeds 20 (±1) % in an optimized thin-film structure.
Jose Ramon Galanmascaros - One of the best experts on this subject based on the ideXlab platform.
-
identification of a nonanuclear coii9 polyoxometalate cluster as a homogeneous catalyst for water oxidation
ChemInform, 2013Co-Authors: Sara Gobernaferron, Laura Vigara, Joaquin Sorianolopez, Jose Ramon GalanmascarosAbstract:In the presence of the polyanion {Co9(H2O)6(OH)3 (HPO4)2 (PW9O34)3}16- catalytic water electrolysis in a sodium phosphate buffer solution at neutral pH occurs on fluorine-doped tin oxide coated Glass Electrodes at reasonable low overpotentials.
-
identification of a nonanuclear coii9 polyoxometalate cluster as a homogeneous catalyst for water oxidation
Inorganic Chemistry, 2012Co-Authors: Sara Gobernaferron, Laura Vigara, Joaquin Sorianolopez, Jose Ramon GalanmascarosAbstract:The polyanion of formula {Co9(H2O)6(OH)3(HPO4)2(PW9O34)3}16– (Co9) contains a central nonacobalt core held together by hydroxo and hydrogen phosphate bridges and supported by three lacunary Keggin-type polyphosphotungstate ligands. Our data demonstrate that Co9 is a homogeneous catalyst for water oxidation. Catalytic water electrolysis on fluorine-doped tin oxide coated Glass Electrodes occurs at reasonable low overpotentials and rates when Co9 is present in a sodium phosphate buffer solution at neutral pH. We carried out our experiments with an excess of 2,2′-bipyridyl as the chelating agent for free aqueous CoII ions, in order to avoid the formation of a cobalt oxide film on the electrode, as observed for other polyoxometalate catalysts. In these conditions, no heterogeneous catalyst forms on the anode, and it does not show any deposited material or significant catalytic activity after a catalytic cycle. Co9 is also an extremely robust catalyst for chemical water oxidation. It is able to continuously ca...