فهرست مطالب

Analytical & Bioanalytical Electrochemistry
Volume:10 Issue: 3, Mar 2018

  • تاریخ انتشار: 1397/01/30
  • تعداد عناوین: 10
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  • Afsaneh Hajializadeh, Somayeh Tajik *, Shohreh Jahani, Hadi Beitollahi Pages 292-301
    A novel modified graphite screen printed electrode (SPE) is prepared as an electrochemical sensor for determination of levodopa. The experimental results suggest that a screen printed electrode (SPE) modified with Cu(II) nanocomplex, [CuCl2(salophen)].H2O (salophen= o-phenylenediaminebis(salicylidenaminato)), accelerates the electron transfer reactions of levodopa. The fabricated sensor revealed some advantages such as convenient preparation, good stability and high sensitivity. The DPV data in 0.1 M phosphate buffer solution (PBS) (pH 7.0) allowed a method to be developed for the determination of levodopa concentrations in the ranges 5.0–900.0 μM, with the detection limits of 0.9 μM. The proposed method was successfully applied to determinations of levodopa in urine samples.
    Keywords: Levodopa, Cu(II) nanocomplex, Graphite screen printed electrode, Voltammetry
  • Volodymyr V. Tkach *, Yana G. Ivanushko, Iryna L. Kukovs´Ka, Lyudmyla V. Romaniv, Svitlana M. Lukanovas., Iacute, Lvio C. De Oliveira, Gleison A. Casagrande, Reza Ojani, Petr, Oacute, I. Yagodynets Pages 302-309
    The possibility of allopurinol electrochemical detection, assisted by pervanadylvanadyl redox pair, has been evaluated from the theoretical point of view. The correspondent mathematical model has been developed and analyzed by means of linear stability theory and bifurcation analysis. It was shown that the steady-state stability in this system is maintained easily. The electroanalytical process is diffusion-controlled. The oscillatory behavior in this system is more probable than for general case, due to the presence of electrostatic and DELinfluencing factors.
    Keywords: Allopurinol, Pervanadyl-vanadyl redox pair, Electrochemical sensors, Electrochemical oscillations, Steady-state stability
  • Behrouz Sabour* Pages 310-320
    In this paper, oleic acid capped iron oxide nanoparticles (OA-IONPs) is prepared through a simple and efficient electrochemical synthetic route. OA-IONPs were synthesized from the Fe(III) nitrate (0.005 M) and 10 cc oleic acid dissolved in ethanol (96%) solution with applying 5 mA cm–2. The prepared IONPs were characterized by different techniques of XRD, FE-SEM, TEM, FT-IR, TGA, DLS and VSM. The OA layer on the surfaces of IONPs was confirmed by FT-IR, DLS and DSC-TGA analyses. The magnetic analysis by VSM revealed that the prepared OA-IONPs exhibit negligible Mr and Ce values at the condition of H→0, implicating their superparamagnetic nature.
    Keywords: Nanoparticles, Cathodic Electrodeposition, In situ capping, Oleic acid
  • K. R. Mahanthesha, B. E. Kumara Swamy* Pages 321-337
    A simultaneous determination of Norepinephrine (NE) using Sodium alpha olefin sulfonate/multi-walled carbon nanotube modified carbon paste electrode was developed by voltammetric techniques. The modified electrode shows excellent electrocatalytic activity towards the oxidation of NE in phosphate buffer solution (PBS) of pH 6.8. The electrochemical studies of scan rate, reveals the overall electrode process for NE was controlled by adsorption and for Epinephrine was diffusion. The pH studies confirm that an equal number of protons and electrons were involved in the electrochemical detection of NE. The lower limit of detection of NE and EP was discussed. The interference studies showed that the modified electrode exhibits excellent selectivity in the presence of large excess of Epinephrine (EP). The separation of the oxidation peak potentials for NE–EP was about 0.203 V. This peak difference was large enough to determine NE and EP individually and simultaneously. This method offers a simple and easy approach to selectively detect various bioactive molecules.
    Keywords: Sodium alpha olefin sulfonate, Multi-walled carbon nanotube, Norepinephrine, Epinephrine, Selective, Electrochemical sensor
  • Isa Karimzadeh * Pages 338-348
    Cd2 doped iron oxide nanoparticles (Cd-IONs) with magnetite crystal structure and 10-20 nm sizes were prepared through cathodic electro-synthesis (CES) method. In this procedure, IONs are galvanostatically deposited on stainless steel cathode with applying simple electrochemical conditions. The prepared both IONs were used as supercapacitor electrode material and their performances were determined through cyclic voltammetry (CV) and galvanostat charge-discharge (GCD) tests. The Cd-IONs sample exhibited specific capacitance as high as 206 F g−1 and cycling stability of 93.9% after 2000 cycling at 0.5 A g−1. The electrochemical data confirmed the proper capacitive ability of the Cd-IONs.
    Keywords: Iron oxide, Nanoparticles, Cd2+ doping, Electrosynthesis, Supercapacitors
  • R. Shashanka* Pages 349-361
    The nanostructured duplex stainless steel powders were prepared by specially designed dual drive planetary mill and their microstructural studies were carried out by using scanning electron microscope (SEM) and X-ray diffraction (XRD). The fabricated duplex stainless steels were consolidated by pressureless sintering method at 1100, 1200 and 1300 ˚C respectively at a load of 700MPa. Density, microhardness, microstructure and pitting corrosion of all the sintered duplex stainless steel samples were studied. The corrosion studies were carried out at 0.5, 1 and 2 M concentration of NaCl solution at different quiet time of 2, 6 and 10 seconds by linear sweep voltammetry (LSV) method. Duplex stainless steel samples sintered at 1300 ˚C shows better pitting corrosion resistance than the stainless steel samples consolidated at 1100 and 1200 ˚C. This is due to the improved densification with increase in sintering temperature. The microstructure of corroded duplex stainless steel samples were studied by using field emission scanning electron microscope (FESEM) and optical microscope.
    Keywords: Stainless steel, Corrosion, Linear sweep voltammetry, Pitting potential, Planetary milling
  • Fazel Ghahramanifard, Ahmad Rouhollahi*, Omid Fazlolahzadeh Pages 362-371
    n-type Copper-doped zinc oxide nanorods (CZO NRs) were electrodeposited on fluorine-doped tin oxide (FTO) substrates at low temperature. Nanorod array morphology with wurtzite hexagonal structure was characterized by SEM and XRD. XRD patterns show CZO NRs growth along c-axis perpendicular to the plane of the glass substrate and Cu2 ions substituted with Zn2 ions and did not change the hexagonal wurtzite structure of the ZnO nanorods. EDX spectra show the presence of Cu in the sample. UV-Vis spectra indicate optical band gap of ZnO narrow by Cu doping. Mott-Schottky analysis reveals that prepared CZO NRs has n-type conductivity. Voltammetry analysis shows CZO NRs have the electrocatalytic activity toward CO2 reduction at
    Keywords: ZnO nanorods, Carbon dioxide, Mott-Schottky, Electrodeposition
  • Chenthattil Raril, Jamballi G. Manjunatha* Pages 372-382
    Glycine was used to fabricate a modified electrode, as a highly sensitive voltammeric sensor and was used for the determination of Nigrosine (NG) in 0.2 M phosphate buffer solution (PBS) having pH 6.0. A fast and easy method for the fabrication of polyglycine modified carbon paste electrode (PGMCPE) by cyclic voltammetry was used. The resulted modified electrode shows superior electrocatalytic activity towards the oxidation of NG compare with (BCPE) in 0.2 M PBS at 6.0 pH. The electrode surfaces were characterized by Field emission scanning electron microscopy (FESEM). The effect of various experimental parametrers on the voltammetric response of NG were investigated. At optimum conditions, the sensor has a linear response in the concentration range of 3×10-5 to 5×10-5 M and 6×10-5 to 1×10-4 M with the limit of detection 8×10-8 M and limit of quantification 2.6×10-7 M. The modified electrode demonstrated having many advantages such as simple preparation, high sensitivity, and low detection of limit, excellent catalytic activity, and reproducibility.
    Keywords: Nigrosine, Carbon paste electrode, Electropolymerization, Cyclic voltammetry
  • Sayed Zia Mohammadi, Elnaz Reiahipour *, Farideh Mosazadeh Pages 383-393
    In the present study, a novel electrochemical sensor involving magnetic core shell nanoparticles (MCSNP) was developed for the detection of imipramine. The screen-printed electrode (SPE) with several advantages, including low cost, versatility and miniaturization was employed. On the other hand, the magnetic core shell nanoparticles were casted on the surface of SPE to obtain MCSNP/SPE. The proposed nanosensor has excellent performance such as high sensitivity and analytical application in real samples. The combination of MCSNP with the SPE is favorable for amplifying electrochemical signals. Under optimized conditions, square wave voltammetry exhibited linear dynamic ranges from 1.0×10-6– 2.0×10-4 M with detection limit of 1.8×10-7 M.
    Keywords: Imipramine determination, Magnetic core shell nanoparticles, Screen-printed electrode
  • Mohammad Reza Ganjali, Eslam Pourbasheer *, Morteza Rezapour Pages 394-403
    In this work, we report dextran capped Gd3+doped Fe3O4 nanoparticles prepared through a novel and facile electrodeposition method. The properties of the nanoparticles such as size, percentage of dextran capped layer, crystallinity, and magnetic properties were evaluated through XRD, IR, FE-SEM, VSM and DSC-TGA techniques. The electrodeposited IONs showed saturation magnetization of 18.02 emu g–1, remanent magnetization of 0.063 emu g–1 and coercivity of 2.59 G, and have superparamagnetic nature. Based on the obtained results, the developed electrochemical synthesis method is proposed as an easy route for the fabrication of superparamagnetic polymer-grafted and metal-ion doped iron oxide nanoparticles.
    Keywords: Magnetic materials, Gd doping, Nanoparticles, Electrochemical synthesis, Dextran