The electrochemical behavior of a copper oxide electrode produced by annealing and electrochemical methods was studied in an acetonitrile solvent by means of the cyclic voltammetry method. The presence of different peaks of oxidation and reduction produced by repeating the potential scans, numerous variations in the current, and shifts of peak potentials in consecutive cycles have been justified. Voltammograms proved that various oxidation species can be produced in solid-deposited forms of Cu2Os and CuOs and dissolved forms of Cu(II)sol and Cu(I)sol ions. The experimental results indicated that higher amounts of Cu2Os than CuOs can be produced in the process of copper electrode annealing. Also, the nature of copper species is responsible for different peak currents in the cyclic voltammograms, characterized by UV–Vis and XRD spectrometric methods.
The electrosynthesis of polypyrrole (PPy) film has been achieved on glassy carbon electrode (GCE) in aqueous medium of Congo red (CR) by means of cyclic voltammetry (CV). The modified electrode exhibits high electrocatalytic activity toward dopamine (DA) oxidation, with drastic enhancement of the reversibility and peak currents. This modified electrode, due to electrostatic interactions, is capable to mask the response of ascorbic acid (AA) completely and provide an effective method for the detection of minor amounts of dopamine in the presence of high concentrations of AA. The electrochemical response of the film modified electrode is strongly dependent to the switching potential applied in the CV procedure of the electro‐polymerization. The results show that by increasing the switching potential more than 0.75 V, the peak of AA is gradually disappeared. This peak in potential of 0.85 V is reached to capacitive background current. With respect to the destruction of the conjugated structure of ppy and lowering the conductivity of the film at the surface of modified electrode, higher switching potentials cannot be suitable for electropolymerization procedure. The effects of various experimental parameters such as, number of polymerization cycles, switching potential, pH and potential sweep rate on the voltammetric response of dopamine were also investigated. The modified electrode shows a linear response to DA in the range of 0.5 to 100 μM with a detection limit of 0.1 μM. The prepared modified electrode does not show any considerable response toward sulfhydryl compounds, such as, cysteine, penicillamine and glutathione, revealing a good selectivity for voltammetric response to DA. The effective electrocatalytic property, ability for masking the voltammetric responses of the other biological reducing agents together with high reproducibility and stability make the modified electrode suitable for selective and sensitive voltammetric detection of sub‐micromolar amounts of DA in clinical and pharmaceutical preparations. 相似文献
In this work, we study the relativistic oscillators in a noncommutative space and in a magnetic field. It is shown that the effect of the magnetic field may compete withthat of the noncommutative space and that is able to vanish the effect of the noncommutative space. 相似文献
This paper contains a discussion of a relativistic spin-0 system in the presence of a Gödel-type background space-time. The Duffin–Kemmer–Petiau (DKP) equation in the presence of a Gödel-type background space-time is studied in detail. After a derivation of the final form of this equation in the considered framework, free spin-0 particles have been studied. 相似文献
We investigate the relativistic dynamics of a Dirac field in the Som–Raychaudhuri space-time, which is described by a Gödel-type metric and a stationary cylindrical symmetric solution of Einstein field equations for a charged dust distribution in rigid rotation. In order to analyze the effect of various physical parameters of this space-time, we solve the Dirac equation in the Som–Raychaudhuri space-time and obtain the energy levels and eigenfunctions of the Dirac operator by using the Nikiforov–Uvarov method. We also examine the behaviour of the Dirac oscillator in the Som–Raychaudhuri space-time, in particular, the effect of its frequency and the vorticity parameter. 相似文献
Molecular Diversity - In this research, we synthesized the Fe3O4/CuO/ZnO@MWCNT magnetic nanocomposites using water extract of Petasites hybridus rhizome, and the high performance of synthesized... 相似文献
Separation of compounds out of complex mixtures is a key issue that has been solved for small molecules by chromatography. However, general methods for the separation of large bio-particles, such as cells, are still challenging. We demonstrate integration of imprinted polymeric films (IPF) into a microfluidic chip, which preferentially capture cells matching an imprint template, and separate strains of cyanobacteria with 80-90% efficiency, despite a minimal difference in morphology and fluorescence, demonstrating its general nature. It is currently thought that the imprinting process, conducted while the polymer cures, transfers chemical information of the cell's external structure to the substrate. Capture specificity and separation can be further enhanced by orienting the imprints parallel to the flow vector and tuning the pH to a lower range. 相似文献
The temperature of a dielectric surface irradiated by a laser pulse can be measured by recording the time-resolved resistance change of a thin platinum stripe vapor-deposited on this surface. Results are reported for quartz and glass surfaces exposed to a pulsed CO2 laser, showing heating rates in excess of 108 K/s. 相似文献