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61.
Electrodeposition of Cobalt Oxide Nanostructure on the Glassy Carbon Electrode for Electrocatalytic Determination of para‐Nitrophenol 下载免费PDF全文
Abdollah Noorbakhsh Mohsen Mosavi Mirkalaei Mohammad H. Yousefi Sohrab Manochehri 《Electroanalysis》2014,26(12):2716-2726
Cobalt oxide nanostructure (CoOxNS) deposited on the glassy carbon (GC) electrode surface is proposed as a novel electrocatalytic system for the reduction of para‐Nitrophenol. Cyclic voltammetry, electrochemical impedance spectroscopy, atomic force microscopy and scanning electron microscopy were used for characterization of deposited CoOxNS. CoOxNS deposited by cycling at positive potentials (0 to +1.3 V) show less charge‐transfer resistance (Rct) and more catalytic activity for the electroreduction of p‐nitrophenol compared to those CoOxNS obtained by scanning the applied potential throughout a negative V range. The GC/CoOxNS electrode showed good electrocatalytic activity toward the reduction of p‐nitrophenol at different pH values. 相似文献
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In this research a novel osmium complex was used as electrocatalyst for electroreduction of oxygen and H2O2 in physiological pH solutions. Electroless deposition at a short period of time (60 s), was used for strong and irreversible adsorption of 1,4,8,12‐tetraazacyclotetradecane osmium(III) chloride (Os(III)LCl2) ClO4 onto single‐walled carbon nanotubes (SWCNTs) modified GC electrode. The modified electrode shows a pair of well defined and reversible redox couple, Os(IV)/Os(III) at wide pH range (1–8). The glucose biosensor was fabricated by covering a thin film of glucose oxidase onto CNTs/Os‐complex modified electrode. The biosensor can be used successfully for selective detection of glucose based on the decreasing of cathodic peak current of oxygen. The fabricated biosensor shows high sensitivity, 826.3 nA μM?1cm?2, low detection limit, 56 nM, fast response time <3 s and wide calibration range 1.0 μM–1.0 mM. The biosensor has been successfully applied to determination of glucose in human plasma. Because of relative low applied potential, the interference from electroactive existing species was minimized, which improved the selectivity of the biosensor. The apparent Michaelis‐Menten constant of GOx on the nanocomposite, 0.91 mM, exhibits excellent bioelectrocatalytic activity of immobilized enzyme toward glucose oxidation. Excellent electrochemical reversibility, high stability, technically simple and possibility of preparation at short period of time are of great advantages of this glucose biosensor. 相似文献
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Ahmad Motahari Abbas Ali Rostami Abdollah Omrani Morteza Ehsani 《Journal of Macromolecular Science: Physics》2015,54(5):517-532
The thermal degradation kinetics of diglycidyl ether of bisphenol-A (DGEBA) cured with tryptophan (Trp) in the presence of silica nanoparticles (SiNP) was investigated by thermogravimetry analysis. The activation energies of the solid-state decomposition process were evaluated using the advanced isoconversional method. The dependence of conversion (degradation) on the temperature and activation energy was determined allowing the calculation of master plots. The experimental master plots agreed with the first-order (F1) kinetic function for both neat epoxy and nanocomposite in the conversion range of 0.45–0.85. Using the kinetic model and the calculated kinetic parameters, the times at half conversion (α = 0.5) were computed for different degradation temperatures. The kinetic analysis showed that the degradation rate of the epoxy nanocomposite was lower than that of the neat epoxy for conversions between 0.45 and 0.85. Therefore, we concluded that adding SiNP to DGEBA/Trp can improve the thermal stability in the conversion range of 0.45–0.85. 相似文献
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Abdollah Salimi Roaya Zand‐Karimi Abdollah Noorbakhash Saied Soltanian 《Electroanalysis》2010,22(20):2434-2442
For the first time silicon nitride (Si3N4) nanoparticles was used for preparation electrochemical biosensor. GOx immobilized on the Si3N4 nanoparticles exhibits facile and direct electrochemistry. The surface coverage and heterogeneous electron transfer rate constant (ks) of immobilized GOx were 6.3×10?13 mol cm?2 and 47.4±0.3 s?1. The sensitivity, linear concentration range and detection limit of the biosensor for glucose detection were 38.57 µA mM?1 cm?2, 25 µM to 8 mM and 6.5 µM, respectively. This biosensor also exhibits good stability, reproducibility and long life time. These indicate Si3N4 nanoparticles is good candidate material for construction of third generation biosensor and bioelectronics devices. 相似文献
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Iridium oxide (IrOx) films formed electrochemically on the surface boron doped diamond electrode by potential cycling in the range −0.2 to 1.2 V from a saturated solution of alkaline iridium(III) solution. A strongly adherent deposit of iridium oxide is formed after 5–10 potential scans. The properties, stability and electrochemical behavior of iridium oxide layers were investigated by atomic force microscopy and cyclic voltammetry. The boron doped diamond (BDD) electrode modified with electrodeposition of a thin film, exhibited an excellent catalytic activity for oxidation of Hg(I) over a wide pH range. The modified electrode shows excellent analytical performance for Hg(I) amperometric detection. The detection limit, sensitivity, response time and dynamic concentration ranges are 3.2 nM, 77 nA μM−1, 100 ms and 5 nM–5 μM. These analytical parameters compare favorably with those obtained with modern analytical techniques and recently published electrochemical methods. 相似文献
69.
Nooshin Movahedian 《Journal of Optimization Theory and Applications》2014,160(2):415-438
In this paper, we pursue two goals. First, we find exact relationships between the three concepts of semismooth sets, functions, and maps. Then, we consider the nonsmooth calculus of these notions. Particularly, we prove that the Mordukhovich and linear subdifferentials (coderivatives) are equal for the semismooth functions (maps). Several examples are presented to illustrate the results of the paper. 相似文献
70.
Babae Robabeh Ghezelbash Mahsa Majd Abdollah Eslami Darbani Seyyed Mohammad Reza 《Journal of Russian Laser Research》2022,43(2):162-168
Journal of Russian Laser Research - In this paper, we use laser-induced breakdown spectroscopy (LIBS) to investigate the laser-induced copper plasma with and without an external magnetic field,... 相似文献