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    Direct electron transfer of myoglobin on CdO nanoparticles modified glassy carbon electrode

    , Article International Journal of Electrochemical Science ; Volume 8, Issue 5 , 2013 , Pages 7345-7356 ; 14523981 (ISSN) Mohammadi, N ; kakavandi, Y. G ; Movassagh, A. A ; Nasereslami, S ; Mohseni, G ; Hajiosseinlo, A ; Sofimaryo, L ; Soleimani, R ; Akbari-dastjerdi, H ; Negahdary, M ; Sharif University of Technology
    In this study, direct electron transfer of myoglobin (Mb) on cadmium oxide (CdO) nanoparticles modified glassy carbon electrode (GCE) was investigated. Prepared CdO nanoparticles were studied by X-Ray diffraction (XRD) and UV-visible absorption methods. All electrochemical studies were performed by cyclic voltammetry (CV) and a potentiostat device. The cyclic voltammogram of Mb/ CdO Nps/ GCE showed a couple of stable redox and oxidative peaks at -470 and -370 mV at scan rate of 50 mVs-1, respectively. The formal potential (Eo) of myoglobin was calculated as -(420 ± 3) mV. Direct electrode transfer led to design a biosensor for determination of hydrogen peroxide (H2O2). The sensor sensitivity... 

    Preparation of Tthin Film CdS/CdTe Solar Cells: Containing CdS Nanowires and CdTe Particles

    , M.Sc. Thesis Sharif University of Technology Akhlaghi, Mohammad Hossein (Author) ; Mohammadi, Mohammad Reza (Supervisor)
    In the present work, we have designed a novel CdS/CdTe solar cell based on CdS nanowires, as a window layer, and CdTe nanoparticles, as a absorber layer. CdS nanowires and CdTe nanoparticles were synthesized by solvothermal method. The samples were characterized by X-ray diffraction diffractometer (XRD), field emission scanning electron microscope (FE-SEM), Atomic Force Microscope (AFM) and Ultraviolet–Visible (UV–vis) spectroscopy spectrometer. Photocurrent measurements were carried out using a 150 W xenon lamp with an air-mass (AM) 1.5 filter. The performance of the solar cell based on the CdS nanowire (NW-CdS) film with 225 nm thickness and CdTe nanoparticle (NP-CdTe) film with 6 μm... 

    Morphological manipulation of solvothermal prepared CdSe nanostructures by controlling the growth rate of nanocrystals as a kinetic parameter

    , Article Journal of Electronic Materials ; Volume 41, Issue 11 , 2012 , Pages 3050-3055 ; 03615235 (ISSN) Zarghami, V ; Mohammadi, M. R ; Fray, D. J ; Sharif University of Technology
    The morphological manipulation, structural characterization, and optical properties of different cadmium selenide (CdSe) nanostructures are reported. Two different CdSe nanostructures, i.e., nanorods and nanoparticles, were grown by controlling the concentration of precursors (i.e., cadmium nitrate and selenium dioxide) in ethanolamine solvent. By manipulating the kinetic parameter of the process (i.e., growth rate) under constant growth driving force (i.e., degree of supersaturation), the morphology of CdSe nanostructures can be tailored from nanorods to nanoparticles. The optical properties of CdSe nanostructures were investigated using ultraviolet-visible (UV-vis) spectroscopy. The... 

    Colloidal Synthesis of CdSe Nanoparticles and the Influence of Processing Parameters on Growth kinetics

    , M.Sc. Thesis Sharif University of Technology Mansouri, Hamid (Author) ; Asgari, Sirous (Supervisor)
    Over the past two decades, several studies have been investigated on synthesis and properties of semi-conductor quantum dots because of their applications in sensors, LEDs, detectors, solar cells, etc. One of challenging issues in synthesizing these nano-particles is their size distribution. In this study, Cadmium Selenide was synthesized by the method of colloidal synthesis. X-ray diffraction showed that the crystalline nano-particles have wurtzite structure. For obtaining a uniform size distribution, effect of various parameters such as molar ratio of components and reaction temperature on the growth kinetics of these particles, were studied. Results showed that molar ratio of Selenium to... 

    Near-white emitting QD-LED based on hydrophilic CdS nanocrystals

    , Article Journal of Luminescence ; Volume 132, Issue 2 , 2012 , Pages 467-473 ; 00222313 (ISSN) Molaei, M ; Marandi, M ; Saievar Iranizad, E ; Taghavinia, N ; Liu, B ; Sun, H. D ; Sun, X. W ; Sharif University of Technology
    In this work we report fabrication of a nanocrystal (NC)-based hybrid organicinorganic LED with structure of ITO/PEDOT:PSS/PVK/CdS-NCs/(Al or Mg:Ag). The hydrophilic CdS NCs were synthesized using a novel aqueous thermochemical method at 80 °C and sizes (around 2 nm) were controlled by thioglycolic acid (TGA) as the capping agent. The favorite feature of these NCs is their relatively high emission intensity and broad, near-white emission. The hydrophilic CdS NCs were successfully spin coated using Triton X-100 as the wetting agent. The fabricated LEDs demonstrated a turn on voltage about 7 V for Al metallic contact. The electroluminescence was a broad spectrum at 540 and 170 nm width, which... 

    Polyrotaxane capped quantum dots as new candidates for cancer diagnosis and therapy

    , Article Journal of Nanostructured Polymers and Nanocomposites ; Volume 7, Issue 1 , 2011 , Pages 18-31 ; 17904439 (ISSN) Sarabi, R. S ; Sadeghi, E ; Hosseinkhani, H ; Mahmoudi, M ; Kalantari, M ; Adeli, M ; Sharif University of Technology
    Molecular self-assembly of cadmium selenide quantum dots-end-capped polyrotaxane hybrid nanostructures (PRCdSe QDs) was led to a new type of core-shell hybrid nanomaterials consisting of cadmium selenide quantum dot (CdSe QDs) core and polyrotaxane shell (PR@QDs). Structure of PR@QDs was characterized using various techniques. It has been observed that the size of PR@QDs was between 20-25 nm in which diameter of core and thickness of shell were between 15-20 and 2-3 nm, respectively. Short-term in vitro cytotoxicity tests, using MTT (3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, were conducted on mouse tissue connective fibroblast adhesive cell line (L929) in order to... 

    Synthesis, characterization and fluorescence spectra of mixed ligand Zn(II), Cd(II) and Hg(II) complexes with 1,10-phenanthroline-5,6-dione ligand

    , Article Journal of Coordination Chemistry ; Volume 60, Issue 15 , 2007 , Pages 1629-1635 ; 00958972 (ISSN) Boghaei, D. M ; Behzadian Asl , F ; Sharif University of Technology
    The novel mixed ligand complexes [M(bpy)(phen-dione)](PF6)2 (M = Zn(II), Cd(II) and Hg(II), bpy = 2,2′-bipyridine and phen-dione = 1,10-phenanthroline-5,6-dione) have been synthesized and characterized by elemental analysis, IR, 1H NMR and electronic absorption spectroscopies. The ν(C=O) of coordinated phen-dione in these complexes are very similar to the free phen-dione ligand showing that phen-dione is not coordinated to metal ion from its C=O sites. Absorption spectra of the complexes show two absorption bands for intraligand transitions. These absorption bands show dependence to the dielectric constant of solvent. These complexes exhibit an intensive fluorescence band around 535 nm in... 

    Synthesis, characterization and fluorescence spectra of mononuclear Zn(II), Cd(II) and Hg(II) complexes with 1,10-phenanthroline-5,6-dione ligand

    , Article Journal of Coordination Chemistry ; Volume 60, Issue 3 , 2007 , Pages 347-353 ; 00958972 (ISSN) Boghaei, D. M ; Behzadian Asl, F ; Sharif University of Technology
    The mononuclear complexes of Zn(II), Cd(II) and Hg(II), [Zn(phen-dione)Cl2], [Cd(phen-dione)Cl2] and [Hg(phen-dione)Cl2], where phen-dione = 1,10-phenanthroline-5,6-dione, have been synthesized and characterized by elemental analysis and IR, 1H NMR and electronic absorption spectroscopies. The ν(C=O) of coordinated phen-dione ligands in these complexes shows that the phen-dione is not coordinated to metal ion from its C=O sites. Electronic spectra of the complexes show two absorption bands for intraligand transitions. These absorption bands show dependence on the dielectric constant of solvents. These complexes exhibit an intense fluorescence band around 545 nm in DMSO when the excitation... 

    Voltammetric monitoring of Cd (II) by nano-TiO2 modified carbon paste electrode sensitized using 1,2-bis-[o-aminophenyl thio] ethane as a new ion receptor

    , Article Sensors and Actuators, B: Chemical ; Vol. 192 , 2014 , pp. 648-657 ; ISSN: 09254005 Ramezani, S ; Ghobadi, M ; Bideh, B. N ; Sharif University of Technology
    The objective of the work ahead is presentation of a new carbon paste electrode (CPE) modified by TiO2 nanoparticles (TiO2NPs) and 1,2-bis-[o-aminophenyl thio] ethane (APTE) ligand as a selective cation receptor for determination of the Cd (II) ions using differential pulse anodic stripping voltammetry (DPASV). The electrode shows an excellent tendency to Cd (II) ions in presence of some interfering species. Under the optimum conditions, a linear calibration curve was obtained in the concentration range of 2.9 nM to 4.6 μM with a correlation coefficient of 0.9969 in the anodic potential of 0.54 (V vs. Ag/AgCl). The metal detection limit was 2.0 nM after 10 min preconcentration (S/N = 3). The... 

    Effect of hydrazine hydrate on the luminescence properties of MPA capped CdTe nanocrystals in hot injection method

    , Article Journal of Luminescence ; Vol. 156, issue , 2014 , p. 235-239 Mobedi, N ; Marandi, M ; Zare Bidaki, H ; Sharif University of Technology
    In this research MPA capped CdTe nanocrystals with sizes around 2.7-3.5 nm were grown in aqueous solution. The process was performed through the reaction of NaHTe with MPA and CdCl2 solution in high temperature. The synthesis was carried out in two different states of standard and modified forms. In the modified synthesis, the hydrazine hydrate material was added to the MPA plus CdCl2 solution before injection. The evolution of the nanocrystals size and PL quantum yield was monitored during the heating time for the growth. The results demonstrated that for the standard synthesis the growth rate was slow. The CdTe nanocrystals with high PL quantum yields were achieved in more than 10 h of... 

    How CdS nanoparticles can influence TiO2 nanotube arrays in solar energy applications?

    , Article Applied Catalysis B: Environmental ; Volume 162 , January , 2015 , Pages 210-216 ; 09263373 (ISSN) Qorbani, M ; Naseri, N ; Moradlou, O ; Azimirad, R ; Moshfegh, A. Z ; Sharif University of Technology
    Elsevier  2015
    In this study, titanium dioxide (TiO2) nanotube array (TNA) films are fabricated via anodization of titanium (Ti) sheet. After annealing, the films consisted of well ordered, vertically oriented TNAs of 125±6nm diameter, 38±3nm wall thickness, and 2.9±0.3μm in length. Cadmium sulfide (CdS) nanoparticles are deposited on the synthesized TNAs by sequential-chemical bath deposition (S-CBD) method with different immersion cycle (n) to produce heterogeneous TNA/CdS-n (n=10, 20 and 30) nanostructures. UV-visible absorption spectra of the samples revealed that the absorption edge of CdS modified TNAs was shifted to a higher wavelength with respect to the pure TNAs indicating band gap reduction of... 

    Controlled nucleation and growth of CdS nanoparticles by turbulent dispersion

    , Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 81, Issue 2 , 2010 ; 15393755 (ISSN) Shayeganfar, F ; Javidpour, L ; Taghavinia, N ; Rahimi Tabar, M. R ; Sahimi, M ; Bagheri Tar, F ; Sharif University of Technology
    We propose and test a method for controlling the size of nanoparticles, which plays a fundamental role in their electrical, optical, and mechanical properties. The method utilizes turbulent mixing, and is applicable to the fabrication of any type of nanoparticle that uses a solution environment in the preparation process. We show by well-controlled experiments on the CdS nanoparticles, which are semiconducting materials, that the average size □d□ of the particles decreases with Reynolds number Re  

    Novel aspects of application of cadmium telluride quantum dots nanostructures in radiation oncology

    , Article Applied Physics A: Materials Science and Processing ; Volume 123, Issue 8 , 2017 ; 09478396 (ISSN) Fazaeli, Y ; Zare, H ; Karimi, S ; Rahighi, R ; Feizi, S ; Sharif University of Technology
    Springer Verlag  2017
    In the last two decades, quantum dots nanomaterials have garnered a great deal of scientific interest because of their unique properties. Quantum dots (QDs) are inorganic fluorescent nanocrystals in the size range between 1 and 20 nm. Due to their structural properties, they possess distinctive properties and behave in different way from crystals in macro scale, in many branches of human life. Cadmium telluride quantum dots (CdTe QDs) were labeled with 68Ga radio nuclide for fast in vivo targeting and coincidence imaging of tumors. Using instant paper chromatography, the physicochemical properties of the Cadmium telluride quantum dots labeled with 68Ga NPs (68Ga@ CdTe QDs) were found high... 

    Molecular dynamics simulation of formation and growth of CdS nanoparticles

    , Article Molecular Simulation ; Vol. 40, issue. 5 , Jul , 2014 , p. 361-369 ; ISSN: 08927022 Shayeganfar, F ; Eskandari, Z ; Rahimi Tabar, M. R ; Sahimi, M ; Sharif University of Technology
    Monodispersed semiconducting nanoparticles are usually synthesised in a liquid medium using injection of an appropriate solution. A key factor in attaining a narrow particle size distribution (PSD) is the temporal separation of the nucleation and growth stages, where the former takes place during the injection. Faster injection produces a larger number of nuclei and a narrower PSD. The injection speed is expected to affect the diffusion of the ions in the solution and to create uniformly high supersaturation for a short period of time. In this paper, we study the growth of CdS nanoparticles during the injection by molecular dynamics simulation. A solution of Cd ions is injected into the... 

    Synthesis and Optical Properties of Cadmium Selenide Thin Films and Nanowires

    , M.Sc. Thesis Sharif University of Technology Kalhori, Hossein (Author) ; Iraji Zad, Azam (Supervisor) ; Dolati, Abolghasem (Supervisor)
    The interesting properties of metallic and semiconductor nanowires provide many applications in electronic and optoelectronic devices. In this project, we have synthesized Cu and CdSe nanowires using electrodeposition method. To adjust deposition bath conditions and characterize the structure of deposit first we prepared CdSe thin film on ITO substrates. The used solution was contained 0.1 M CdSO4+ 0.1 mM SeO2 in the acidic situation with pH=2.5. The best reduction potential was determined about -0.5 V. The XPS and XRD analyses showed that the ratio of cadmium to selenium in the films was 1:1 and the film’s structure is amorphous. Optical band gap of the cadmium selenide films was obtained... 

    , M.Sc. Thesis Sharif University of Technology Rahmani, Atefeh (Author) ; Gholami, Mohammad Reza (Supervisor)
    Nanosized CdS coupled TiO2 nanocrystals were prepared by a microemulsion-mediated Hydrothermal method at relatively low temperatures. Modification of this nanocomposite with Tyrosine,Phenylalanine,Glysine and Glutamate ,especially Tyrosine resulted in enhanced photocatalytic degradation rate of Nitrobenzene( NB ) compared to using CdS-TiO2 under visible light irradiation. The prepared samples were characterized by BET,SEM, XRD, UV–Vis spectroscopy ,FTIR .It was found which have high surface area about 470 m2 g−1 and mesoporous character with the average pore diameter of 2.8 nm.The results showed this nanocomposite consisted of uniform anatase TiO2 with highly dispersed cubic phase CdS... 

    Synthesis of CdTe Quantum Dots for Light Emitting Diodes and Chemical Sensing Applications

    , Ph.D. Dissertation Sharif University of Technology Zare, Hakimeh (Author) ; Akhavan, Omid (Supervisor) ; Taghavinia, Nima (Supervisor)
    Luminescent semiconductor nanocrystals otherwise known as quantum dots (QDs) have attracted intense interest over the past decade due to their unique properties and great potential in various applications. In this work we have studied the growth and luminescence properties of CdTe QDs and CdTe/CdS core-shell QDs and their application in hybrid organic/inorganic light-emitting diodes (LEDs) and fluorescent sensors. CdTe QDs were synthesized using a thermochemical method in aqueous phase. Central composite design (CCD) was applied to obtain the optimized conditions of the synthesis. The effects of four independent parameters including molar ratios of Cd to Te ions, TGA to Te ions, pH of the... 

    Synthesis and Characterization of ZnO Nanostructure, Modified by Graphene and CdS for PEC Application

    , M.Sc. Thesis Sharif University of Technology Nourmohammadi, Mohammad Amin (Author) ; Moshfegh, Alireza (Supervisor)
    In this project, the photoelectrochemical properties of ZnO nanostructures modified by CdS and Graphene was studied. Firs, titanium foil was cut into rectangular shape with 1cm width and 3 cm length, cleaned by rinsing in acetone and ethanol and annealed at 4000C for an hour. As a result, a thin layer of titanium oxide was formed on Ti sheet. Then a layer of grapheme oxide was deposited on substrate using Electrophoretic deposition (EPD). After that, ZnO nanostructure was deposited on the TiO2 substrate using Electropulsation (EP) with 20 consecutive pulse followed by 3 minutes Electrodeposition (ED). Using SEM analysis, the morphology of ZnO was determined to be nanopetals in which the... 

    Synthesis and Characterization of Nanostructured Cadmium Tellurides for Solar Cell Application

    , M.Sc. Thesis Sharif University of Technology Ranjbarzadeh, Shahin (Author) ; Mohammadi, Mohammad Reza (Supervisor)
    Recently, synthesis of nanostructured CdTe of II-VI semiconductors has caused much attention due to their great potential in many optoelectronic applications such as solar cells and detectors. Among different synthesis methods, solvothermal process is a suitable method due to low temperature synthesis. In this work CdTe nanoparticles, nanowires, nanorods and nanobelts with cubic structure (zincblende) were synthesized via a simple solvothermal method at a moderate temprature. The effect of processing parameters on some properties sush as crystal structure, morphology, crystallite size chemical bond configuration and optical properties of synthesized CdTe were investigated. It was found that,... 

    Cadmium telluride quantum dots induce apoptosis in human breast cancer cell lines

    , Article Toxicology and Industrial Health ; Volume 34, Issue 5 , 2018 , Pages 339-352 ; 07482337 (ISSN) Naderi, S ; Zare, H ; Taghavinia, N ; Irajizad, A ; Aghaei, M ; Panjehpour, M ; Sharif University of Technology
    SAGE Publications Ltd  2018
    Introduction: Semiconductor quantum dots (QDs), especially those containing cadmium, have undergone marked improvements and are now widely used nanomaterials in applicable biological fields. However, great concerns exist regarding their toxicity in biomedical applications. Because of the lack of sufficient data regarding the toxicity mechanism of QDs, this study aimed to evaluate the cytotoxicity of three types of QDs: CdTe QDs, high yield CdTe QDs, and CdTe/CdS core/shell QDs on two human breast cancer cell lines MDA-MB468 and MCF-7. Methods: The breast cancer cells were treated with different concentrations of QDs, and cell viability was evaluated via MTT assay. Hoechst staining was...