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    Electrochemical determination of atorvastatin on nano-scaled polypyrrole film

    , Article Bioelectrochemistry ; Vol. 98 , 2014 , pp. 1-10 ; ISSN: 15675394 Kamalzadeh, Z ; Shahrokhian, S ; Sharif University of Technology
    Pyrrole was electro-polymerized on the surface of the glassy carbon electrode (GCE) coated with a thin film of carbon nanomaterials, including carbon nanotubes (CNTs), carbon nanoparticles (CNPs), nanodiamond-graphite (NDG) or graphite nanopowder (GNP). Morphology, thickness, stability and loading of the polypyrrole (PPY) film were significantly affected by the structure and morphology of the sub-layer of carbon nanomaterials. Electrochemical oxidation of atorvastatin (ATOR) was investigated. Under the optimized conditions, a significant increase in the peak current (compared to other modified electrodes and bare GCE) and a negative shift in the peak potential (compared to bare GCE) were... 

    Nickel hydroxide nanoparticles-reduced graphene oxide nanosheets film: Layer-by-layer electrochemical preparation, characterization and rifampicin sensory application

    , Article Talanta ; Vol. 119 , 2014 , pp. 156-163 ; ISSN: 00399140 Rastgar, S ; Shahrokhian, S ; Sharif University of Technology
    Electrochemical deposition, as a well-controlled synthesis procedure, has been used for subsequently layer-by-layer preparation of nickel hydroxide nanoparticle-reduced graphene oxide nanosheets (Ni(OH)2-RGO) on a graphene oxide (GO) film pre-cast on a glassy carbon electrode surface. The surface morphology and nature of the nano-hybrid film (Ni(OH)2-RGO) was thoroughly characterized by scanning electron and atomic force microscopy, spectroscopy and electrochemical techniques. The modified electrode appeared as an effective electro-catalytic model for analysis of rifampicin (RIF) by using linear sweep voltammetry (LSV). The prepared modified electrode exhibited a distinctly higher activity... 

    Adsorptive stripping differential pulse voltammetric determination of mebendazole at a graphene nanosheets and carbon nanospheres/chitosan modified glassy carbon electrode

    , Article Sensors and Actuators, B: Chemical ; Volume 185 , 2013 , Pages 669-674 ; 09254005 (ISSN) Ghalkhani, M ; Shahrokhian, S ; Sharif University of Technology
    For the first time graphene nanosheets and carbon nanospheres/chitosan (GNS-CNS/CS) based nanocomposite film modified electrode was used for the electro-oxidation of mebendazole (MD). MD is a benzimidazole drug that is used to treat human infections caused by parasitic worms. MD causes slow immobilization and death of the worms by selectively and irreversibly blocking uptake of glucose. The electrochemical behavior of MD at GNS-CNS/CS modified glassy carbon electrode has been investigated using cyclic and differential pulse voltammetry in aqueous media at different pHs. The prepared electrode showed an excellent electrochemical activity toward the electro-oxidation of MD leading to a... 

    Amplified electrochemical DNA sensor based on polyaniline film and gold nanoparticles

    , Article Electroanalysis ; Volume 25, Issue 6 , 2013 , Pages 1373-1380 ; 10400397 (ISSN) Saberi, R. S ; Shahrokhian, S ; Marrazza, G ; Sharif University of Technology
    In this work, an electrochemical DNA biosensor, based on a dual signal amplified strategy by employing a polyaniline film and gold nanoparticles as a sensor platform and enzyme-linked as a label, for sensitive detection is presented. Firstly, polyaniline film and gold nanoparticles were progressively grown on graphite screen-printed electrode surface via electropolymerization and electrochemical deposition, respectively. The sensor was characterized by scanning electron microscopy (SEM), cyclic voltammetry and impedance measurements. The polyaniline-gold nanocomposite modified electrodes were firstly modified with a mixed monolayer of a 17-mer thiol-tethered DNA probe and a spacer thiol,... 

    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
    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... 

    Electrochemistry of levo-thyroxin on edge-plane pyrolytic graphite electrode: application to sensitive analytical determinations

    , Article Electroanalysis ; Volume 23, Issue 8 , JUL , 2011 , Pages 1875-1880 ; 10400397 (ISSN) Khafaji, M ; Shahrokhian, S ; Ghalkhani, M ; Sharif University of Technology
    The electrochemical response of sodium levo-thyroxin (T4) at the surface of an edge plane pyrolytic graphite (EPPG) electrode is investigated using cyclic voltammetric technique in the presence of 0.1M HCl as supporting electrolyte. T4 underwent totally irreversible oxidation at this system and a well-defined peak at 821mV was obtained. Compared to the signals obtained in the optimized conditions at bare glassy carbon and carbon paste electrodes, the oxidation current of T4 at an EPPG electrode was greatly enhanced. The electrochemical process of T4 was explored and the experimental conditions were optimized. The oxidation peak current represented a linear dependence on T4 concentration from... 

    Application of carbon nanoparticle/chitosan modified electrode for the square-wave adsorptive anodic striping voltammetric determination of Niclosamide

    , Article Electrochemistry Communications ; Volume 12, Issue 1 , 2010 , Pages 66-69 ; 13882481 (ISSN) Ghalkhani, M ; Shahrokhian, S ; Sharif University of Technology
    A new modified electrode formed by carbon nanoparticle/chitosan film (CNP/CS) was used for electrocatalytic reduction of Niclosamide (NA). The electrochemical behavior of NA at the CNP/CS modified electrode was investigated in detail by the means of cyclic voltammetry. The reduction mechanism of NA, corresponds to the redox chemistry of nitro group, was thoroughly investigated. The effect of the experimental parameters e.g. potential and time of accumulation, pH of the buffered solutions and potential sweep rate on the response of the electrode was studied. The prepared electrode showed high stability and uniformity in the composite film, short response time, good reproducibility and an... 

    Development of a nanocellulose composite based voltammetric sensor for vitamin B9 analysis

    , Article Current Nanoscience ; Volume 12, Issue 4 , 2016 , Pages 493-499 ; 15734137 (ISSN) Ghalkhani, M ; Shahrokhian, S ; Sharif University of Technology
    Bentham Science Publishers B.V 
    As a B group vitamins, vitamin B9 is a Water-soluble vitamin which is produced by plants and microorganisms (bacteria and yeasts). Vitamin B9 plays an important role in the production of proteins and nucleic acids in body and also is one of the substances that prevents the development of neural tube defects in the fetus. Methods: Electrochemical behavior of vitamin B9 was studied using a potentiostat/galvanostat SAMA 500, electroanalyzer system, I. R. Iran. A three-electrode system was used, including a glassy carbon working electrode (d = 2.0 mm, purchased from Azar Electrode Co., Urmia, I.R. Iran), an Ag/AgCl (saturated KCl) reference electrode and a Pt wire auxiliary electrode.... 

    In-situ fabrication of nanosheet arrays on copper foil as a new substrate for binder-free high-performance electrochemical supercapacitors

    , Article Journal of Electroanalytical Chemistry ; Volume 802 , 2017 , Pages 48-56 ; 15726657 (ISSN) Mohammadi, R ; Shahrokhian, S ; Sharif University of Technology
    A facile hydrothermal method and subsequent electroactivation have been developed to fabricate three-dimensional (3D) CuO nanosheet arrays on the copper foil substrate, which can be used directly as a binder-free electrode for supercapacitor applications. Under optimum conditions, by using this facile method, a high capacitance of 125 mF/cm2 at a current density of 0.3 mA/cm2 is obtained. The prepared supercapacitor showed a good rate capability (46.4% capacitance retention, when the current density is increased to more than 30 times) and an excellent cyclability (more than 88% capacitance retention after 3000 cycles). © 2017 Elsevier B.V  

    A high performance supercapacitor based on graphene/polypyrrole/Cu2O-Cu(OH)2 ternary nanocomposite coated on nickel foam

    , Article Journal of Physical Chemistry C ; Volume 121, Issue 12 , 2017 , Pages 6508-6519 ; 19327447 (ISSN) Asen, P ; Shahrokhian, S ; Sharif University of Technology
    A simple and low-cost electrochemical deposition method is used to prepare reduced graphene oxide/polypyrrole/Cu2O-Cu(OH)2 (RGO/PPy/Cu2O-Cu(OH)2) ternary nanocomposites as the electrode material for supercapacitor application. First, graphene oxide-polypyrrole (GO/PPy) nanocomposite is electrochemically synthesized on Ni foam by electro-oxidation of pyrrole monomer in an aqueous solution containing GO and Tiron. Subsequently, the GO/PPy film is converted to the corresponding reduced form (RGO/PPy) by an effective and eco-friendly electrochemical reduction method. Then, a thin layer of Cu2O-Cu(OH)2 is formed on RGO/PPy film by chronoamperometry. The RGO/PPy/Cu2O-Cu(OH)2 nanocomposite is... 

    Design and fabrication of an electrochemical aptasensor using Au nanoparticles/carbon nanoparticles/cellulose nanofibers nanocomposite for rapid and sensitive detection of Staphylococcus aureus

    , Article Bioelectrochemistry ; Volume 123 , 2018 , Pages 70-76 ; 15675394 (ISSN) Ranjbar, S ; Shahrokhian, S ; Sharif University of Technology
    Elsevier B.V  2018
    Since that pathogenic bacteria are major threats to human health, this paper describes the fabrication of an effective and durable sensing platform based on gold nanoparticles/carbon nanoparticles/cellulose nanofibers nanocomposite (AuNPs/CNPs/CNFs) at the surface of glassy carbon electrode for sensitive and selective detection of Staphylococcus aureus (S. aureus). The AuNPs/CNPs/CNFs nanocomposite with the high surface area, excellent conductivity, and good biocompatibility was used for self-assembled of the thiolated specific S. aureus aptamer as a sensing element. The surface morphology of AuNPs/CNPs/CNFs nanocomposite was characterized with field emission scanning electron microscopy... 

    Advanced binder-free electrode based on core–shell nanostructures of mesoporous Co3V2O8-Ni3V2O8 thin layers@porous carbon nanofibers for high-performance and flexible all-solid-state supercapacitors

    , Article Chemical Engineering Journal ; Volume 341 , 2018 , Pages 10-26 ; 13858947 (ISSN) Hosseini, H ; Shahrokhian, S ; Sharif University of Technology
    Elsevier B.V  2018
    The development of thin layer structures on flexible current collectors has become as an effective strategy for preparing advanced portable and wearable power sources. Herein, a flexible and efficient electrode was fabricated based on electrospun porous carbon nanofibers (PCNFs) substrate with elaborately designed thin layer Co3V2O8-Ni3V2O8 core–shell nanostructures (Co3V2O8-Ni3V2O8 TLs@PCNFs). The resulting free-standing Co3V2O8-Ni3V2O8 TLs@PCNFs composite was used directly as a flexible electrode in three electrode system for supercapacitor studies without the need for utilization of either binder or metal-based current collector. The unique thin layer structure of Co3V2O8-Ni3V2O8... 

    Vanadium dioxide-anchored porous carbon nanofibers as a Na+ intercalation pseudocapacitance material for development of flexible and super light electrochemical energy storage systems

    , Article Applied Materials Today ; Volume 10 , 2018 , Pages 72-85 ; 23529407 (ISSN) Hosseini, H ; Shahrokhian, S ; Sharif University of Technology
    Elsevier Ltd  2018
    The development of a flexible binder free electrode based on 3D vanadium dioxide (VO2) nano-architectures has materialized as an effective strategy for fabrication of advanced wearable, portable, and stretchable electronic devices. However, most of the stretchable energy storage devices based on VO2 suffer from a relatively low operating voltage, high weight, low specific capacitance, and thus low energy density. Here, a novel binder free supercapacitor electrode composed of hierarchical VO2 nanosheet arrays grown on porous carbon nanofibers (VO2@PCNFs) is designed using a simple hydrothermal method followed by annealing treatment. The electrochemical evaluation confirmed that the energy... 

    Ternary nickel cobalt iron sulfides ultrathin nanosheets grown on 3-D nickel nanocone arrays‑nickel plate current collector as a binder free electrode for fabrication of highly performance supercapacitors

    , Article Journal of Electroanalytical Chemistry ; Volume 810 , 2018 , Pages 78-85 ; 15726657 (ISSN) Rahimi, S ; Shahrokhian, S ; Hosseini, H ; Sharif University of Technology
    Elsevier B.V  2018
    The design of 3-dimensional (3-D) nanostructured materials on the novel current collectors has recently considered as a promising strategy for developing high-performance supercapacitors. Herein, in the first step, a novel 3-D nickel nanocone arrays (NCAs) are synthesized on the surface of nickel plate (NP) by a one-step electrodeposition method without using any template (NCAs-NP). Then, a simple and efficient method is developed for fabricating ternary metal sulfides electrodes based on the electrodeposition of nickel cobalt iron sulfide (Ni-Co-Fe-S) ultrathin nanosheets on the surface of NCAs-NP. Taking advantages of the unique flower like structure of Ni-Co-Fe-S ultrathin nanosheets and... 

    Nanoporous gold as a suitable substrate for preparation of a new sensitive electrochemical aptasensor for detection of salmonella typhimurium

    , Article Sensors and Actuators, B: Chemical ; Volume 255 , 2018 , Pages 1536-1544 ; 09254005 (ISSN) Ranjbar, S ; Shahrokhian, S ; Nurmohammadi, F ; Sharif University of Technology
    Elsevier B.V  2018
    Nowadays, achievement to easy, fast, reliable and cost-effective techniques and tools is one of the most important challenges in detection of microorganisms. Salmonella typhimurium is one of the most important pathogenic bacteria that affect the human health and environmental infections. In this work we report a new, stable, biocompatible and cost-effective platform for construction of an aptasensor based on nanoporous gold (NPG) for detection of S. typhimurium. Nanoporous gold is electrochemically synthesized using Au-Cu alloy at the surface of Au/GCE. Thiol functionalized aptamer is used for effective linking to the surface of NPG/Au/GCE via self-assemble monolayers (SAMs) formation.... 

    Hydrogen bubble template fabricated nano-architecture quaternary dendritic sulfide as cathode and electro-etched carbon fiber paper as anode electrode for total novel binder-free asymmetric supercapacitors

    , Article Journal of Alloys and Compounds ; Volume 811 , 2019 ; 09258388 (ISSN) Mohammadi, R ; Naderi, L ; Shahrokhian, S ; Sharif University of Technology
    Elsevier Ltd  2019
    A novel electrode consisting of 3D porous nickel‒cobalt‒copper sulfide dendritic structures is synthesized, in which, for the first time ternary Ni–Co–Cu foam is constructed through hydrogen bubble template and followed by sulfidization via a hydrothermal reaction in thiourea. The 3D, porous Ni–Co–Cu dendritic sulfide electrode exhibits a high specific capacitance of 1203.75 F g−1 (0.963 F cm−2) at current of 1.0 mA and excellent cycling stability, excellent ratability along with high cycle stability. An asymmetric supercapacitor (ASC) using dendritic sulfide structures and reduced electro-etched carbon fiber paper (RECF) as the positive and negative electrodes, respectively is developed.... 

    Self-supported nanoporous Zn–Ni–Co/Cu selenides microball arrays for hybrid energy storage and electrocatalytic water/urea splitting

    , Article Chemical Engineering Journal ; Volume 375 , 2019 ; 13858947 (ISSN) Hosseini, H ; Shahrokhian, S ; Sharif University of Technology
    Elsevier B.V  2019
    The phase-pure multiple ternary or quaternary metal selenides in energy boosting, have not been reported yet. Here, self-supported porous crystalline Zn–Ni–Co/Cu selenides microballs arrays were constructed by selenation of the designed tubular Cu(OH)2 arrays decorated with ultrathin Zn–Co–Ni tri-metallic hydroxide on carbon cloth substrate. For this rational engineering, a novel precursor sample was firstly prepared by conversion of deposited Cu layer to hollow tubular Cu(OH)2 arrays on carbon cloth, then, Zn-Co–Ni layered ternary hydroxides with a thin layer structure was deposited around this tubular arrays. The selenation with an exciting morphology change from amorphous tube to highly... 

    Direct growth of nickel-cobalt oxide nanosheet arrays on carbon nanotubes integrated with binder-free hydrothermal carbons for fabrication of high performance asymmetric supercapacitors

    , Article Composites Part B: Engineering ; Volume 172 , 2019 , Pages 41-53 ; 13598368 (ISSN) Hekmat, F ; Shahrokhian, S ; Hosseini, H ; Sharif University of Technology
    Elsevier Ltd  2019
    A high performance asymmetric supercapacitor (ASC)has been fabricated by using nickel oxide-cobalt oxide nanosheets (NiO–CoO NSs), which were directly grown on carbon nanotubes (CNTs)and hydrothermal carbon spheres (HTCs)as positive and negative electrodes, respectively. Both electrode materials are binder-free prepared by using a catalytic chemical vapour deposition (CVD)approach followed by a facile hydrothermal method for cathode and a one-step environmental-friendly route called hydrothermal carbonization for anode. Using NiO–CoO NSs@CNTs and HTCs, which were directly grown on Ni foam, not only leads to a very small equivalent series resistance, but also provides an impressive capacitive... 

    Electrochemical sensing based on carbon nanoparticles: A review

    , Article Sensors and Actuators, B: Chemical ; Volume 293 , 2019 , Pages 183-209 ; 09254005 (ISSN) Asadian, E ; Ghalkhani, M ; Shahrokhian, S ; Sharif University of Technology
    Elsevier B.V  2019
    The emergence of nanoscience and nanotechnology has opened up new horizons to researchers. In this regard, carbon nanomaterials are considered as the cornerstone of numerous investigations. Among various carbon nanostructures, “Carbon nanoparticles (CNPs)” have attracted a great deal of attention during the past few years due to their unique properties such as high surface area, non-toxicity, biocompatibility as well as simple and low-cost synthetic procedures via environmentally friendly routes. Thanks to these properties along with their interesting optical behavior, CNPs have found diverse applications in the fields of bioimaging, nanomedicine, photo/electro-catalysis, and bio/chemical... 

    Enhanced electrochemical activity of a hollow carbon sphere/polyaniline-based electrochemical biosensor for HBV DNA marker detection

    , Article ACS Biomaterials Science and Engineering ; Volume 5, Issue 5 , 2019 , Pages 2587-2594 ; 23739878 (ISSN) Salimian, R ; Shahrokhian, S ; Panahi, S ; Sharif University of Technology
    American Chemical Society  2019
    Herein, we present a novel, simple, and ultrasensitive electrochemical DNA (E-DNA) sensor based on hollow carbon spheres (HCS) decorated with polyaniline (PANI). A thiolated 21-mer oligonucleotide, characteristic of HBV DNA, is immobilized via electrodeposited gold nanoparticles on HCS-PANI. Cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) are used to characterize the electrochemical properties of the prepared nanocomposite. Scanning electron microscopy is employed to investigate the morphological texture of the fabricated modifier. An enhanced intrinsic signal of PANI is probed to evaluate the biosensing ability of the prepared...