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    Construction of Pt nanoparticle-decorated graphene nanosheets and carbon nanospheres nanocomposite-modified electrodes: Application to ultrasensitive electrochemical determination of cefepime

    , Article RSC Advances ; Volume 4, Issue 15 , 2014 , Pages 7786-7794 ; ISSN: 20462069 Shahrokhian, S ; Hosseini Nassab, N ; Ghalkhani, M ; Sharif University of Technology
    Abstract
    A novel ultrasensitive modified electrode was fabricated with a graphene nanosheets and carbon nanospheres (GNS-CNS)-based nanocomposite film as a powerful platform. Pt nanoparticles (PtNPs) were simply electrodeposited onto the GNS-CNS-coated glassy carbon electrode creating a PtNPs/GNS-CNS hybrid nanocomposite modified electrode. Scanning electron microscopy, energy dispersive X-ray spectroscopy and linear sweep voltammetry (LSV) techniques were used for the characterization of the prepared modified electrode. The results of investigation of electrochemical response characteristics of cefepime (CP) revealed a considerable improvement in the oxidation peak current of CP on PtNPs/GNS-CNS/GCE... 

    Modification of a glassy carbon electrode with a bilayer of multiwalled carbon nanotube/benzene disulfonate-doped polypyrrole: Application to sensitive voltammetric determination of olanzapine

    , Article RSC Advances ; Vol. 4, Issue. 76 , Aug , 2014 , pp. 40553-40560 ; ISSN: 20462069 Shahrokhian, S ; Azimzadeh, M ; Hosseini, P ; Sharif University of Technology
    Abstract
    A glassy carbon electrode was coated with a thin layer of multi-walled carbon nanotubes and subsequently was electro-polymerized with polypyrrole. The prepared electrode was used for the voltammetric determination of olanzapine (OLZ). The peak current of OLZ increases remarkably on the surface of the modified electrode. This is due to the large increase in the microscopic area of the electrode surface along with the strong adsorption of OLZ on the surface of the electrode. The film modifier was characterized by scanning electron microscopy, atomic force microscopy and cyclic voltammetry techniques. Experimental variables, such as deposited amount of nanotube suspension, pH of the supporting... 

    Fabrication of an electrochemical sensor based on the electrodeposition of Pt nanoparticles on multiwalled carbon nanotubes film for voltammetric determination of ceftriaxone in the presence of lidocaine, assisted by factorial-based response-surface methodology

    , Article Journal of Solid State Electrochemistry ; Vol. 18, issue. 1 , 2014 , p. 77-88 Shahrokhian, S ; Hosseini-Nassab, N ; Kamalzadeh, Z ; Sharif University of Technology
    Abstract
    A glassy carbon electrode (GCE) is modified with platinum nanoparticle (PtNPs) decorated multiwalled carbon nanotube (MWCNT). The modified electrode is applied for the determination of ceftriaxone (CFX) in the presence of lidocaine. Different methods were used to characterize the surface morphology of the modified electrode. The electrochemical behavior of CFX was investigated at GCE, MWCNT/GCE and PtNPs/MWCNT/GCE. A factorial-based response-surface methodology was used to find out the optimum conditions with minimum number of experiments. Under the optimized conditions, oxidation peak currents increased linearly with CFX concentration in the range of 0.01-10.00 μM with a detection limit of... 

    Electrodeposition of Pt-Ru nanoparticles on multi-walled carbon nanotubes: Application in sensitive voltammetric determination of methyldopa

    , Article Electrochimica Acta ; Volume 58, Issue 1 , 2011 , Pages 125-133 ; 00134686 (ISSN) Shahrokhian, S ; Rastgar, S ; Sharif University of Technology
    2011
    Abstract
    A modified glassy carbon electrode, prepared by potentiostatic electrodeposition of platinum-ruthenium nanoparticles (Pt-RuNPs) onto a multi-walled carbon nanotube (MWCNT) layer, offers dramatic improvements in the stability and sensitivity of voltammetric responses toward methyldopa (m-dopa) compared to glassy carbon electrodes individually coated with MWCNT or Pt-RuNPs. The surface morphology and nature of the hybrid film (Pt-RuNPs/MWCNT) deposited on glassy carbon electrodes was characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. A remarkable enhancement in the microscopic area of the electrode together... 

    Glassy carbon electrode modified with a bilayer of multi-walled carbon nanotube and polypyrrole doped with new coccine: Application to the sensitive electrochemical determination of Sumatriptan

    , Article Electrochimica Acta ; Volume 56, Issue 27 , November , 2011 , Pages 10032-10038 ; 00134686 (ISSN) Shahrokhian, S ; Kamalzadeh, Z ; Saberi, R. S ; Sharif University of Technology
    2011
    Abstract
    A promising electrochemical sensor was developed based on a layer by layer process by electro-polymerization of pyrrole in the presence of new coccine (NC) as dopant anion on the surface of the multi-walled carbon nanotubes (MWCNTs) pre-coated glassy carbon electrode (GCE). The modified electrode was used as a new and sensitive electrochemical sensor for voltammetric determination of sumatriptan (SUM). The electrochemical behavior of SUM was investigated on the surface of the modified electrode using linear sweep voltammetry (LSV). The results showed a remarkable increase (∼12 times) in the anodic peak current of SUM in comparison to the bare GCE. The effect of experimental variables such... 

    Modification of glassy carbon electrode with a bilayer of multiwalled carbon nanotube/tiron-doped polypyrrole: Application to sensitive voltammetric determination of acyclovir

    , Article Materials Science and Engineering C ; Volume 53 , 2015 , Pages 134-141 ; 09284931 (ISSN) Shahrokhian, S ; Azimzadeh, M ; Amini, M. K ; Sharif University of Technology
    Elsevier Ltd  2015
    Abstract
    A novel voltammetric sensor based on glassy carbon electrode (GCE) modified with a thin film of multi-walled carbon nanotubes (MWCNTs) coated with an electropolymerized layer of tiron-doped polypyrrole was developed and the resulting electrode was applied for the determination of acyclovir (ACV). The surface morphology and property of the modified electrode were characterized by field emission scanning electron microscopy and electrochemical impedance spectroscopy techniques. The electrochemical performance of the modified electrode was investigated by means of linear sweep voltammetry (LSV). The effect of several experimental variables, such as pH of the supporting electrolyte, drop size of... 

    Application of pyrolytic graphite modified with nano-diamond/graphite film for simultaneous voltammetric determination of epinephrine and uric acid in the presence of ascorbic acid

    , Article Electrochimica Acta ; Volume 55, Issue 28 , 2010 , Pages 9090-9096 ; 00134686 (ISSN) Shahrokhian, S ; Khafaji, M ; Sharif University of Technology
    2010
    Abstract
    A novel modified pyrolytic graphite electrode with nano-diamond/graphite was fabricated. The electrochemical response characteristics of the modified electrode toward the epinephrine (EN) and uric acid (UA) were studied by means of cyclic and linear sweep voltammetry. The structural morphology and thickness of the film was characterized by SEM technique. The prepared electrode showed an excellent catalytic activity in the electrochemical oxidation of EN and UA, leading to remarkable enhancements in the corresponding peak currents and lowering the peak potentials. The prepared modified electrode acts as a highly sensitive sensor for simultaneous determination of EN and UA in the presence of... 

    Simultaneous voltammetric determination of ascorbic acid, acetaminophen and isoniazid using thionine immobilized multi-walled carbon nanotube modified carbon paste electrode

    , Article Electrochimica Acta ; Volume 55, Issue 3 , 2010 , Pages 666-672 ; 00134686 (ISSN) Shahrokhian, S ; Asadian, E ; Sharif University of Technology
    2010
    Abstract
    A carbon paste electrode (CPE) modified with thionine immobilized on multi-walled carbon nanotube (MWCNT), was prepared for simultaneous determination of ascorbic acid (AA) and acetaminophen (AC) in the presence of isoniazid (INZ). The electrochemical response characteristics of the modified electrode toward AA, AC and INZ were investigated by cyclic and differential pulse voltammetry (CV and DPV). The results showed an efficient catalytic role for the electro-oxidation of AA and AC, leading to a remarkable peak resolution (∼303 mV) for two compounds. On the other hand, the presence of INZ, which is considered as important drug interference for AC, does not affect the voltammetric responses... 

    Application of glassy carbon electrode modified with a carbon nanoparticle/melamine thin film for voltammetric determination of raloxifene

    , Article Journal of Electroanalytical Chemistry ; Volume 780 , 2016 , Pages 126-133 ; 15726657 (ISSN) Shahrokhian, S ; Ghalkhani, M ; Balotf, H ; Salimian, R ; Sharif University of Technology
    Elsevier B.V  2016
    Abstract
    As a selective estrogen receptor modulator, raloxifene (RXF) prevent of osteoporosis in postmenopausal women by estrogenic actions on bone and decreases the risk of invasive breast cancer by anti-estrogenic actions on the breast and uterus tissue. However, RXF may increase the risk of blood clots, including deep vein thrombosis and pulmonary embolism. For the first time glassy carbon electrode modified with a thin film of melamine/carbon nanoparticles (CNPs/Mela) was constructed and used for the sensitive voltammetric determination of RXF. In comparison with unmodified electrode, the presence of the CNPs/Mela film resulted in a remarkable increase in the peak currents and sharpness of the... 

    Modified glassy carbon electrodes based on carbon nanostructures for ultrasensitive electrochemical determination of furazolidone

    , Article Materials Science and Engineering C ; Volume 61 , 2016 , Pages 842-850 ; 09284931 (ISSN) Shahrokhian, S ; Naderi, L ; Ghalkhani, M ; Sharif University of Technology
    Abstract
    The electrochemical behavior of Furazolidone (Fu) was investigated on the surface of the glassy carbon electrode modified with different carbon nanomaterials, including carbon nanotubes (CNTs), carbon nanoparticles (CNPs), nanodiamond-graphite (NDG), graphene oxide (GO), reduced graphene oxide (RGO) and RGO-CNT hybrids (various ratios) using linear sweep voltammetry (LSV). The results of voltammetric studies exhibited a considerable increase in the cathodic peak current of Fu at the RGO modified GCE, compared to other modified electrodes and also bare GCE. The surface morphology and nature of the RGO film was thoroughly characterized by scanning electron microscopy (SEM), atomic force... 

    Surface modification of glassy carbon electrode with the functionalized carbon nanotube for ultrasensitive electrochemical detection of risperidone

    , Article Journal of the Iranian Chemical Society ; Volume 15, Issue 7 , July , 2018 , Pages 1485-1494 ; 1735207X (ISSN) Shahrokhian, S ; Hafezi Kahnamoui, M ; Salimian, R ; Sharif University of Technology
    Springer Verlag  2018
    Abstract
    Risperidone (RIS), one of the typical antipsychotics drugs, originally approved to be used for the mental illness treatment, especially schizophrenia, bipolar disorder, autism and major depression. In the present study, different carbon nanostructures including functionalized multi-walled carbon nanotubes (F-MWCNTs), carbon nanoparticles, nanodiamond-graphite and reduced graphene oxide were employed for modification of the surface of glassy carbon electrode (GCE) for ultrasensitive detection of RIS. The most significant increase in the anodic peak current of RIS was observed on F-MWCNTs-modified electrode (compared to the other modified electrodes and bare GCE). The influence of different... 

    Investigation of the electrochemical behavior of tizanidine on the surface of glassy carbon electrode modified with multi-walled carbon nanotube/titan yellow–doped polypyrrole

    , Article Journal of Electroanalytical Chemistry ; Volume 823 , 2018 , Pages 146-154 ; 15726657 (ISSN) Shahrokhian, S ; Shamloofard, M ; Salimian, R ; Sharif University of Technology
    Abstract
    The present paper describes a voltammetric sensor based on glassy carbon electrode (GCE) modified with a thin film of multi-walled carbon nanotubes (MWCNTs) coated with an electro-polymerized layer of titan yellow-doped over–oxidized polypyrrole (OPPY) for the determination of tizanidine (TIZ). A significant enhancement was observed in the anodic peak current of TIZ on the surface of OPPY/CNT/GCE, relative to the bare, CNT- and OPPY-coated GCEs. The microscopic structure and surface morphology of the composite film was thoroughly characterized by means of atomic force microscopy (AFM), scanning electron microscopy (SEM) and cyclic voltammetry (CV) techniques. The effect of various... 

    Application of carbon-paste electrode modified with iron phthalocyanine for voltammetric determination of epinephrine in the presence of ascorbic acid and uric acid

    , Article Sensors and Actuators, B: Chemical ; Volume 137, Issue 2 , 2009 , Pages 669-675 ; 09254005 (ISSN) Shahrokhian, S ; Ghalkhani, M ; Amini, M. K ; Sharif University of Technology
    2009
    Abstract
    A carbon-paste electrode (CPE) modified with iron(II) phthalocyanine was used for the sensitive voltammetric determination of epinephrine (EN). The electrochemical response characteristics of the modified electrode toward EN, ascorbic acid (AA) and uric acid (UA) were investigated by cyclic and differential pulse voltammetry (CV and DPV). The results show an efficient catalytic activity of the electrode for the electro-oxidation of EN, which leads to improvement of reversibility of the electrode response and lowering its overpotential by more than 100 mV. The effect of pH and potential sweep rate on the mechanism of the electrode process was investigated. The modified electrode exhibits an... 

    Electrochemical determination of l-dopa in the presence of ascorbic acid on the surface of the glassy carbon electrode modified by a bilayer of multi-walled carbon nanotube and poly-pyrrole doped with tiron

    , Article Journal of Electroanalytical Chemistry ; Volume 636, Issue 1-2 , 2009 , Pages 40-46 ; 15726657 (ISSN) Shahrokhian, S ; Asadian, E ; Sharif University of Technology
    Elsevier  2009
    Abstract
    There are high attractions in the development of conducting polymer (CP) coatings to improve the electrochemical properties and biocompatibility of electrodes in the area of biosensors. A new type of the modified electrodes is prepared in a layer-by-layer process by using multi-walled carbon nanotube (MWCNT) and poly-pyrrole. In this procedure, the glassy carbon electrode is casted by a drop suspension of MWCNT, which leads to form a thin film of nanotube on its surface. In the second step, electrochemical polymerization of pyrrole in the presence of tiron (used as doping anion) is performed on the surface of the MWCNT pre-coated electrode. The modification procedure led to fabrication of a... 

    Multi-walled carbon nanotubes with immobilised cobalt nanoparticle for modification of glassy carbon electrode: Application to sensitive voltammetric determination of thioridazine

    , Article Biosensors and Bioelectronics ; Volume 24, Issue 11 , 2009 , Pages 3235-3241 ; 09565663 (ISSN) Shahrokhian, S ; Ghalkhani, M ; Adeli, M ; Amini, M. K ; Sharif University of Technology
    2009
    Abstract
    Multi-walled carbon nanotubes (MWCNTs) were immobilised with cobalt nanoparticles and analyzed by transmission electron microscopy. This modification procedure substantially improved colloidal dispersion of the immobilised MWCNTs in water and organic solvents, yielding uniform and stable thin films for modification of the glassy carbon electrode surface. The modified electrode showed an efficient catalytic role for the electrochemical oxidation of thioridazine (TR), leading to remarkable decrease in its oxidation overpotential of approximately 100 mV and enhancement of the kinetics of the electrode reaction, which can be confirmed by increasing in the peak current and sharpness of the peak.... 

    An electrochemical sensing platform based on nitrogen-doped hollow carbon spheres for sensitive and selective isoprenaline detection

    , Article Journal of Electroanalytical Chemistry ; Volume 847 , 2019 ; 15726657 (ISSN) Shahrokhian, S ; Panahi, S ; Salimian, R ; Sharif University of Technology
    Elsevier B.V  2019
    Abstract
    In this work, uniform and monodisperse hollow carbon spheres (HCSs) are synthesized through two different processes using polydopamine (PDA), as a carbon precursor, and silica core as a template, under the modified Stöber condition. The surface morphology of the synthesized structures is characterized by means of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Fourier-transform infrared spectroscopy (FT-IR). In the next step, the electrochemical behavior of isoprenaline (ISPN) is investigated by using glassy carbon electrode modified with a thin film of the synthesized hollow carbon spheres. The electrochemical characterization of the modified electrodes is... 

    Differential pulse voltammetric determination of N-acetylcysteine by the electrocatalytic oxidation at the surface of carbon nanotube-paste electrode modified with cobalt salophen complexes

    , Article Sensors and Actuators, B: Chemical ; Volume 133, Issue 2 , 12 August , 2008 , Pages 599-606 ; 09254005 (ISSN) Shahrokhian, S ; Kamalzadeh, Z ; Bezaatpour, A ; Boghaei, D. M ; Sharif University of Technology
    2008
    Abstract
    The preparation and electrochemical performance of the carbon nanotube-paste electrode modified with salophen complexes of cobalt(III) perchlorate, with various substituents on the salophen ligand, as well as their electrocatalytic activity toward the oxidation of N-acetylcysteine (NAC) is investigated. Several Schiff base complexes containing various nucleophilic and electrophilic functional groups were prepared, and their electrochemical characteristics for the electro-oxidation of NAC were evaluated using cyclic and differential pulse voltammetry (CV and DPV). The results revealed, the modified electrodes show an efficient and selective electrocatalytic activity toward the anodic... 

    Highly sensitive voltammetric determination of lamotrigine at highly oriented pyrolytic graphite electrode

    , Article Bioelectrochemistry ; Volume 84 , 2012 , Pages 38-43 ; 15675394 (ISSN) Saberi, R. S ; Shahrokhian, S ; Sharif University of Technology
    2012
    Abstract
    The electrochemical behavior of lamotrigine (LMT) at the pyrolytic graphite electrode (PGE) is investigated in detail by the means of cyclic voltammetry. During the electrochemical reduction of LMT, an irreversible cathodic peak appeared. Cyclic voltammetric studies indicated that the reduction process has an irreversible and adsorption-like behavior. The observed reduction peak is attributed to a two-electron process referring to the reduction of azo group. The electrode showed an excellent electrochemical activity toward the electro-reduction of LMT, leading to a significant improvement in sensitivity as compared to the glassy carbon electrode. The results of electrochemical impedance... 

    Selective voltammetric determination of d-penicillamine in the presence of tryptophan at a modified carbon paste electrode incorporating TiO2 nanoparticles and quinizarine

    , Article Journal of Electroanalytical Chemistry ; Volume 644, Issue 1 , Jan , 2010 , Pages 1-6 ; 15726657 (ISSN) Mazloum Ardakani, M ; Beitollahi, H ; Taleat, Z ; Naeimi, H ; Taghavinia, N ; Sharif University of Technology
    2010
    Abstract
    A carbon paste electrode (CPE) chemically modified with TiO2 nanoparticles and quinizarine (QZ) was used as a selective electrochemical sensor for the simultaneous determination of minor amounts of d-penicillamine (D-PA) and tryptophan (Trp). This modified electrode showed very efficient electrocatalytic activity for anodic oxidation of both d-PA and Trp. Substantial decreases of anodic overpotentials for both compounds made this analysis possible. Results of square wave voltammetry (SWV) using this modified electrode showed two well-resolved anodic waves for the oxidation of d-PA and Trp, which makes the simultaneous determination of both compounds possible. The peak potential for the... 

    Simultaneous voltammetric determination of tramadol and acetaminophen using carbon nanoparticles modified glassy carbon electrode

    , Article Electrochimica Acta ; Volume 55, Issue 8 , 2010 , Pages 2752-2759 ; 00134686 (ISSN) Ghorbani Bidkorbeh, F ; Shahrokhian, S ; Mohammadi, A ; Dinarvand, R ; Sharif University of Technology
    2010
    Abstract
    A sensitive and selective electrochemical sensor was fabricated via the drop-casting of carbon nanoparticles (CNPs) suspension onto a glassy carbon electrode (GCE). The application of this sensor was investigated in simultaneous determination of acetaminophen (ACE) and tramadol (TRA) drugs in pharmaceutical dosage form and ACE determination in human plasma. In order to study the electrochemical behaviors of the drugs, cyclic and differential pulse voltammetric studies of ACE and TRA were carried out at the surfaces of the modified GCE (MGCE) and the bare GCE. The dependence of peak currents and potentials on pH, concentration and the potential scan rate were investigated for these compounds...