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    Synthesis of metal nanoparticles using laser ablation technique

    , Article Emerging Applications of Nanoparticles and Architectural Nanostructures: Current Prospects and Future Trends ; March , 2018 , Pages 575-596 ; 9780128135167 (ISBN); 9780323512541 (ISBN) Ganjali, M ; Vahdatkhah, P ; Sharif University of Technology
    Elsevier Inc  2018
    Abstract
    Pulse laser ablation (PLA) technique has been demonstrated to be a simple, compatible, promising, versatile, relatively low-cost, pure, and green approach with the absence of toxic chemicals and reagents for fabrication of metal nanoparticles. Purity is an especially important attribute of metal nanoparticles (NPs) in biological and medical technologies. For such applications, it is crucial to prepare metal NPs with the desired shape and size distribution. This chapter discusses the advantages of the PLA technique as compared with other techniques for metal NPs, explains the various mechanisms involved in the generation of metal NPs, outlines the effects of laser parameters, such as... 

    Preparation and Investigation of the Electrochemical Behavior of Sensors Based on Glassy Carbon Electrode Modified with Various Carbon Nanostructures Decorated by Some of Metal Nanoparticlesfor Determination of Ceftizoxime

    , M.Sc. Thesis Sharif University of Technology Ranjbar, Saba (Author) ; Shahrokhian, Saeed (Supervisor) ; Masoumeh Ghalkhani (Co-Advisor)
    Abstract
    In the recent years, sensors and biosensors attracts much attentions as a suitable devices in analytical chemistry. In this meantime carbon nanostructures and metal nanoparticles act as a good choice owing to their unique properties such as high electrical conductivity andmechanical and chemical stability in modification of the surface of sensors and biosensors. Because of importance of analysis the trace amounts of pharmaceutical and biological compounds, in this studies the surface of glassy carbon electrode was modified with some carbon nanostructures and metal nanoparticles for electrochemical investigation and determination of pharmaceutical and clinical compounds.In the first work, a... 

    Application of Metallic Nanoparticles in Treatment of Wastewater Containing Dyestuffs

    , M.Sc. Thesis Sharif University of Technology Hosseini, Reza (Author) ; Shaygan, Jalalaldin (Supervisor)
    Abstract
    Textile industrial wastewaters are one of the most important sources of environmental contaminants. In the recent years, use of advanced oxidation processes, by producing highly active and reactive components such as hydroxyl radicals has been proposed. The aim of this research is oxidative degradation of methylene blue dye using Cu-nanoparticles immobilized on a polymer support with H2O2 as an oxidant reagent.In general, oxidative degradation of methylene blue with hydrogen proxide in the presence of immobilized CuO nanoparticles on a polymer support as the catalyst was studied. We used polyamidoamine (PAMAM) dendrimer as the polymer support for nanoparticles. fourth generation of PAMAM was... 

    Preparation of Metal Nanoparticles/Ionic Liquid Composites and Investigation of Their Catalytic Activity

    , M.Sc. Thesis Sharif University of Technology Gharegozloo, Nazanin (Author) ; Gholami, Mohammad Reza (Supervisor) ; Salari, Hadi (Co-Advisor)
    Abstract
    In this research Fe3O4 magnetic nanoparticles were prepared. To protect against oxidation, a shell of SiO2 was deposited on Fe3O4. Graphene oxide was prepared by the modified Hummer method and supported on the Fe3O4@SiO2 core-shell. Then, ionic liquid layer was impregnated on it. Afterward, PtAu nano alloy were synthesized on the surface of nanocomposite with the different molar ration including 100:0, 75:25, 50:50, 25:75 and 0:100. The as-prepared nanocomposite was characterized by SEM, XRD, and FT-IR analytical methods.For investigation of kinetically activity of catalysts, reduction of 4-nitrophenol with NaBH4 as reducer was used. The adsorption in different times was obtained by UV-vis... 

    Synthesis and Characterization of TiO2 and WO3 Thin Film Photoanodes Containing Noble Metal Nanoparticles and (TiO2)x-(ZnO)1-x Nanocomposite Photanodes for H2 Production

    , Ph.D. Dissertation Sharif University of Technology Naseri Taheri, Naimeh (Author) ; Moshfegh, Ali Reza (Supervisor)
    Abstract
    Growing demand on energy and limitation and consequence of fossil fuels have caused to utilize the clean and renewable energy sources. Hydrogen is a clean energy carrier which produced just water vapor during combustion. Today, methods which are usually used to produce this fuel are based on using fossil fuel compounds. Therefore, utilizing new production methods is unavoidable. One of these methods is using semiconductors such as TiO2 to spilt water and produce H2 by solar irradiation. Reducing the energy gap of these semiconductors to match the solar spectrum, specially in its visible range, modification of their structures, surfaces and stability are the main challenges in hydrogen... 

    Synthesis of Novel Bimetallic Nanocomposite of Copper and Silver Based on Metal Organic Frameworks and Investigation of Its Application as Catalyst in Sulfonation Reaction

    , M.Sc. Thesis Sharif University of Technology Yaghoubnejad Pazoki, Parisa (Author) ; Matloubi Moghaddam, Firouz (Supervisor)
    Abstract
    In recent years, bimetallic metal-organic frameworks have attracted the great attention of researchers due to their dual properties and synergistic effects. In this research and inspired by green chemistry, the synthesis of a magnetic nanocomposite of the defective green metal-organic framework was implemented, which carries metallic silver nanoparticles (Ag NPs@Cu-MOF). Then, the sulfonated compounds were synthesized with the prepared nanocomposite because of the importance and widespread medicinal use of sulfur-containing compounds especially sulfonated compounds, and the difficulty of their preparation methods. It is noteworthy to mention that the sulfonation reaction was done by... 

    Nanoscale phase behavior on flat and curved membranes

    , Article Nanotechnology ; Vol. 25, issue. 50 , Dec , 2014 Andersen, T ; Bahadori, A ; Ott, D ; Kyrsting, A ; Reihani, S. N. S ; Bendix, P. M ; Sharif University of Technology
    Abstract
    The diverse physical properties of membranes play a critical role in many membrane associated biological processes. Proteins responsible for membrane transport can be affected by the lateral membrane order and lateral segregation of proteins is often controlled by the preference of certain membrane anchors for membrane phases having a physically ordered state. The dynamic properties of coexisting membrane phases are often studied by investigating their thermal behavior. Optical trapping of gold nanoparticles is a useful tool to generate local phase transitions in membranes. The high local temperatures surrounding an irradiated gold nanoparticle can be used to melt a part of a giant... 

    Molecular dynamics study of 'success evaluation' for metallic nanoparticles manipulation on gold substrate

    , Article Micro and Nano Letters ; Volume 5, Issue 5 , 2010 , Pages 286-290 ; 17500443 (ISSN) Mahboobi, S. H ; Meghdari, A ; Jalili, N ; Amiri, F ; Sharif University of Technology
    2010
    Abstract
    One of the key factors in the assembly of nanoparticles and controlled construction of such systems is their positioning by a manipulation system. The response of clusters that are subjected to this process is of great importance. In this study, the behaviour of metallic nanoparticles during the manipulation process on an Au substrate is investigated using molecular dynamics. Two criteria are proposed for the evaluation of success in a pushing process regarding the intactness of a nanoparticle/substrate pair. The effects of cluster material, temperature and manipulation speed on the success of the process are investigated based on the simulation results  

    Molecular dynamics simulation of manipulation of metallic nanoclusters on double-layer substrates

    , Article Physica E: Low-Dimensional Systems and Nanostructures ; Volume 42, Issue 9 , 2010 , Pages 2364-2374 ; 13869477 (ISSN) Mahboobi, S. H ; Meghdari, A ; Jalili, N ; Amiri, F ; Sharif University of Technology
    2010
    Abstract
    Molecular dynamics simulations are carried out to investigate the manipulation of metallic clusters on double-layer surfaces. The system parts are made of transition metals. The conditions which are subjected to change in the tests are material combinations for cluster, main substrate and lubricant layer (adlayer). In addition to qualitative observations, two criteria which represent the particle deformation and substrate abrasion are utilized as evaluation tools and are computed for each case. Obtaining this sort of knowledge is highly beneficial for further experiments in order to be able to plan the conditions and routines, which guarantee better success in the manipulation process  

    Molecular dynamics study of success evaluation for metallic nanoparticles manipulation on gold substrate

    , Article Proceedings of the ASME Design Engineering Technical Conference, 30 August 2009 through 2 September 2009, San Diego, CA ; Volume 6 , 2009 , Pages 345-346 ; 9780791849033 (ISBN) Mahboobi, S. H ; Meghdari, A ; Jalili, N ; Sharif University of Technology
    Abstract
    Using molecular dynamics, the behavior of nanoparticles during manipulation process is investigated in this paper. The system consists of a tip, cluster and substrate. The focus of the present research is on ultra-fine metallic nanoclusters. The system of concern is made of different transition metals. Two criteria have been proposed for evaluation of success in a pushing process. Such criteria describe the intactness of nanoparticle/substrate pair. The effects of cluster material and manipulation speed on the success of the process are investigated by atomistic simulations. Such qualitative simulation studies can evaluate the level of success of manipulation regarding different working... 

    Aggregation-based colorimetric sensor for determination of prothioconazole fungicide using colloidal silver nanoparticles (AgNPs)

    , Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 187 , 2017 , Pages 143-148 ; 13861425 (ISSN) Ivrigh, Z. J. N ; Fahimi Kashani, N ; Hormozi Nezhad, M. R ; Sharif University of Technology
    Abstract
    There is a growing interest in developing high-performance sensors monitoring fungicides, due to their broadly usage and their adverse effects on humans and wildlife. In the present study, a colorimetric probe has been proposed for detection of prothioconazole based on aggregation of unmodified silver nanoparticles (AgNPs). Under optimized condition, linear relationships between the concentration of prothioconazole and the absorbance ratio of A500/A395 were found over the range of 0.01 μg·mL− 1 to 0.4 μg·mL− 1 with quantification limit as low as 1.7 ng·mL− 1. Furthermore, AgNPs color change from yellow to pink-orange in presence of prothioconazole, indicates highly sensitive naked-eye... 

    Noble metal nanoparticles in biosensors: Recent studies and applications

    , Article Nanotechnology Reviews ; Volume 6, Issue 3 , 2017 , Pages 301-329 ; 21919089 (ISSN) Malekzad, H ; Sahandi Zangabad, P ; Mirshekari, H ; Karimi, M ; Hamblin, M. R ; Sharif University of Technology
    Walter de Gruyter GmbH  2017
    Abstract
    The aim of this review is to cover advances in noble metal nanoparticle (MNP)-based biosensors and to outline the principles and main functions of MNPs in different classes of biosensors according to the transduction methods employed. The important biorecognition elements are enzymes, antibodies, aptamers, DNA sequences, and whole cells. The main readouts are electrochemical (amperometric and voltametric), optical (surface plasmon resonance, colorimetric, chemiluminescence, photoelectrochemical, etc.) and piezoelectric. MNPs have received attention for applications in biosensing due to their fascinating properties. These properties include a large surface area that enhances biorecognizers... 

    Silver nanoparticles immobilized onto poly(4-vinylpyridine)-functionalized magnetic nanoparticles: a robust magnetically recyclable catalyst for oxidant-free alcohol dehydrogenation

    , Article Applied Organometallic Chemistry ; Volume 32, Issue 2 , February , 2018 ; 02682605 (ISSN) Bayat, A ; Shakourian Fard, M ; Talebloo, N ; Mahmoodi Hashemi, M ; Sharif University of Technology
    John Wiley and Sons Ltd  2018
    Abstract
    A heterogeneous and recyclable catalyst with a high loading of silver nanoparticles was synthesized via the silver nanoparticles being supported onto the surface of magnetic nanoparticles coated with poly(4-vinylpyridine). The synthesized catalyst was used in the dehydrogenation of alcohols to corresponding carbonyl compounds. A broad diversity of alcohols was converted into their corresponding carbonyl compounds in excellent yields. The catalyst was easily recovered by applying an external magnetic field and reused for seven reaction cycles without considerable loss of activity. The catalyst was fully characterized using various techniques. Copyright © 2017 John Wiley & Sons, Ltd  

    Noble metal nanostructures in optical biosensors: basics, and their introduction to anti-doping detection

    , Article TrAC - Trends in Analytical Chemistry ; Volume 100 , 2018 , Pages 116-135 ; 01659936 (ISSN) Malekzad, H ; Sahandi Zangabad, P ; Mohammadi, H ; Sadroddini, M ; Jafari, Z ; Mahlooji, N ; Abbaspour, S ; Gholami, S ; Ghanbarpoor, M ; Pashazadeh, R ; Beyzavi, A ; Karimi, M ; Hamblin, M. R ; Sharif University of Technology
    Elsevier B.V  2018
    Abstract
    Nanotechnology has illustrated significant potentials in biomolecular-sensing applications; particularly its introduction to anti-doping detection is of great importance. Illicit recreational drugs, substances that can be potentially abused, and drugs with dosage limitations according to the prohibited lists announced by the World Antidoping Agency (WADA) are becoming of increasing interest to forensic chemists. In this review, the theoretical principles of optical biosensors based on noble metal nanoparticles, and the transduction mechanism of commonly-applied plasmonic biosensors are covered. We review different classes of recently-developed plasmonic biosensors for analytic determination... 

    Backscattering-based detection scheme for dark-field optical tweezers

    , Article Journal of the Optical Society of America B: Optical Physics ; Volume 36, Issue 6 , 2019 , Pages 1587-1593 ; 07403224 (ISSN) Samadi, A ; Mousavi, S. M ; Hajizadeh, F ; Reihani, S. N. S ; Sharif University of Technology
    OSA - The Optical Society  2019
    Abstract
    Laser nanomanipulation by metallic nanoparticles, which are smaller than the diffraction limit, has become a great interest, especially in the manipulation of unstained biological samples. However, they are hard to image in bright-field microscopy, because of the diffraction limit. Thus, incorporation of a dark-field microscopy technique with optical tweezers would be an inevitable choice, enforcing the use of the backward scattering detection scheme. Here in this paper, we have taken into account the reflected light from the coverslip along with backscattered light from the trapped particle to validate and reveal some precautions of using this detection scheme, based on Mie-Debye... 

    Utilizing the moiré deflectometry-based detection method improves the detection sensitivity for gold nanoparticles trapped by optical tweezers

    , Article Journal of the Optical Society of America B: Optical Physics ; Volume 38, Issue 7 , 2021 , Pages 2135-2140 ; 07403224 (ISSN) Reihani, S. N ; Khorshad, A. A ; Sharif University of Technology
    The Optical Society  2021
    Abstract
    Gold nanoparticles (GNPs) are very often used as handles for nanotechnological micromanipulation. In this regard, optical trapping of GNPs is of great importance, in which locating the trapped GNP within the focal spot with nanometer precision is crucial. Very recently, we have introduced a new position detection system for optical tweezers based on moiré deflectometry (MD). Here we show, both theoretically and experimentally, that an MD detection system could provide significantly larger detection sensitivity for a trapped GNP compared to that provided by conventional back focal plane (BFP) detection systems. For instance, for a trapped 200 nm GNP, the detection sensitivity provided by the... 

    Useful multivariate kinetic analysis: Size determination based on cystein-induced aggregation of gold nanoparticles

    , Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 115 , 2013 , Pages 588-594 ; 13861425 (ISSN) Rabbani, F ; Nezhad, M. R. H ; Abdollahi, H ; Sharif University of Technology
    2013
    Abstract
    This study describes spectrometric monitored kinetic processes to determine the size of citrate-capped Au nanoparticles (Au NPs) based on aggregation induced by L-cysteine (L-Cys) as a molecular linker. The Au NPs association process is thoroughly dependent on pH, concentration and size of nanoparticles. Size dependency of aggregation inspirits to determine the average diameters of Au NPs. For this aim the procedure is achieved in aqueous medium at pH 7 (phosphate buffer), and multivariate data including kinetic spectra of Au NPs are collected during aggregation process. Subsequently partial least squares (PLS) modeling is carried out analyzing the obtained data. The model is built on the... 

    Multiway investigation of interaction between fluorescence labeled DNA strands and unmodified gold nanoparticles

    , Article Analytical Chemistry ; Volume 84, Issue 15 , July , 2012 , Pages 6603-6610 ; 00032700 (ISSN) Akhlaghi, Y ; Kompany Zareh, M ; Hormozi Nezhad, M. R ; Sharif University of Technology
    ACS  2012
    Abstract
    The single stranded DNA can be adsorbed on the negatively charged surface of gold nanoparticles (AuNPs), but the rigid structure of double stranded DNA prevents it from adsorption. Signal of a tagged single stranded DNA will be quenched by the plasmon effect of the AuNP surface after its adsorption. This phenomenon has been used to study the DNA hybridization and interactions of two complementary 21mer oligonucleotides each tagged with a different fluorescent dye in the presence of 13 nm gold nanoparticles. The DNA strands used in this study belong to the genome of HIV. The obtained rank deficient three-way fluorescence data sets were resolved by both PARAFAC and restricted Tucker3 models.... 

    Novel manufacturing process of nanoparticle/Al composite filler metals of tungsten inert gas welding by accumulative roll bonding

    , Article Materials Science and Engineering A ; Volume 648 , 2015 , Pages 47-50 ; 09215093 (ISSN) Fattahi, M ; Noei Aghaei, V ; Dabiri, A. R ; Amirkhanlou, S ; Akhavan, S ; Fattahi, Y ; Sharif University of Technology
    Elsevier Ltd  2015
    Abstract
    In the present work, accumulative roll bonding (ARB) was used as an effective method for manufacturing nanoparticle/Al composite filler metals of tungsten inert gas (TIG) welding. After welding, the distribution of ceramic nanoparticles and mechanical properties of welds were investigated. By applying ARB, ceramic nanoparticles were uniformly dispersed in the composite filler metals. Consequently, the welds produced by these filler metals had a uniform dispersion of ceramic nanoparticles in their compositions. The test results showed that the yield strength of welds was greatly increased when using the nanoparticle/Al composite filler metals. The improvement in the yield strength was... 

    Voltammetric studies of Azathioprine on the surface of graphite electrode modified with graphene nanosheets decorated with Ag nanoparticles

    , Article Materials Science and Engineering C ; Volume 58 , 2016 , Pages 1098-1104 ; 09284931 (ISSN) Asadian, E ; Iraji Zad, A ; Shahrokhian, S ; Sharif University of Technology
    Elsevier Ltd 
    Abstract
    By using graphene nanosheets decorated with Ag nanoparticles (AgNPs-G) as an effective approach for the surface modification of pyrolytic graphite electrode (PGE), a sensing platform was fabricated for the sensitive voltammetric determination of Azathioprine (Aza). The prepared AgNPs-G nanosheets were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-vis and Raman spectroscopy techniques. The electrochemical behavior of Aza was investigated by means of cyclic voltammetry. Comparing to the bare PGE, a remarkable enhancement was observed in the response characteristics of Aza on the surface of the modified electrode (AgNPs-G/PGE) as well as a noticeable...