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Nano Structures - Volume:8 Issue: 4, Autumn 2018

Journal of Nano Structures
Volume:8 Issue: 4, Autumn 2018

  • تاریخ انتشار: 1397/10/07
  • تعداد عناوین: 12
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  • Majid Masteri, Farahani *, Kiana Khademabbasi, Niloofar Mollatayefeh, Raphael Schneider Pages 325-331
    A new method in differentiation of chiral molecules is reported based on the fluorescence quenching of functionalized CdS quantum dots (CdS-QDs) as nanosensor by differing in the chirality of functionalization species. The chemically functionalized CdS-QDs with strong yellow emission were prepared using chiral L-cysteine (L-Cyst) and D-cysteine (D-Cyst) molecules. Then, the functionalized CdS-QDs were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis, photoluminescence (PL), ultraviolet-visible (UV-Vis), and Fourier transform infrared (FT-IR) spectroscopies. The prepared L- and D-cysteine functionalized CdS-QDs were exploited as fluorescence probes for detection and determination of L-morphine and D-methamphetamine. It was found that the fluorescence of D- and L-cysteine functionalized CdS-QDs were efficiently quenched by adding D-methamphetamine and L-morphine to them, respectively. The magnitude of fluorescence quenching depended on the concentration of L-morphine and D-methamphetamine solutions according to the Stern-Volmer equation. So, the functionalized CdS-QDs can be used as simple, quick, cheap, and sensitive nanosensor for practical detection of morphine and methamphetamine.
    Keywords: Chiral, Cysteine, L-Morphine, D-Methamphetamine, Quantum dot
  • Ratika Komal *, Simran Kashyap Pages 332-342
    Green synthesis of nanoparticles using plants as sources exhibiting superiority over the physical and chemical methods that are expensive and can involve the use of toxic, hazardous chemicals, which may pose biological and environmental risks. In present study silver nanoparticles were synthesized in single step by biological method using extracts of Actinidia deliciosa paste as reducing and stabilizing agent. Extracts were prepared using two different solvents i.e. double distilled water and 70% ethanol by Hot Percolation method. These extracts were augmented with AgNO3 solution and subjected to different reaction conditions i.e. pH and temperature. Synthesized silver nanoparticles of Actinidia deliciosa paste samples were preliminary characterized by using UV-VIS spectrophotometer and also on basis of change in colour in samples. Confirmatory characterization of biologically synthesized silver nanoparticles was done by Energy-Dispersive X-ray Spectroscopy (EDS) for presence of true silver metal ions samples, Transmission Electron Microscopy (TEM) so as to find out the shape and size of silver nanoparticles. The MIC test was performed to evaluate antimicrobial activity of silver nanoparticles against E.coli, Staphylococcus aureus, Pseudomonas aeruginosa. Applicative test of biosynthesized silver nanoparticles for detection of minimum concentration of Hg2+ heavy metal ions in contaminated water sample was done by observing change in optical density with respect to fixed silver nanoparticles concentration and varied Hg2+ heavy metal ions concentration by using UV-VIS spectrophotometer at wavelength of 630 nm.
    Keywords: Actinidia Deliciosa Paste, Antimicrobial Activity, EDS, Heavy Metal Ions Detection, Silver Nanoparticles, TEM
  • Ghodsi Mohammadi Ziarani *, Elham Tavaf, Parisa Gholamzadeh, Alireza Badiei Pages 343-349
    A one pot four-component reaction of 9,10-phenanthraquinone, aromatic aldehyde, aniline, and ammonium acetate was designed for the preparation of tetrasubstituted imidazoles (phenanthro[9,10-d]imidazole) derivatives in the presence of SBA-Pr-SO3H as a mesoporous solid acid catalyst. Phenanthro[9,10-d]imidazole derivatives were produced by the use of this technique in short reaction times and good to high yields. SBA-15 (Santa Barbara Amorphous), as a hexagonal mesoporous silica with 6 nm pore diameter, was synthesized and then its internal surface was modified with (3-mercaptopropyl)trimethoxysilane following an oxidation process to gain SBA-Pr-SO3H. The latter was then characterized; SEM image showed uniform particles about 700-900 nm and TEM image demonstrated the presence of parallel channels, which resemble the pores configuration of SBA-15. Additionally, the weight reduction in TGA curve in the temperature range of 200-600 °C (about 20% mass loss) established that the anchored propyl sulfonic acid groups onto the SBA-15 pores is about 1.2 mmol/g. This data was also confirmed by back-titration of SBA-Pr-SO3H with standardized NaOH and HCl solutions.
    Keywords: Tetrasubstituted imidazoles, Phenanthro[9, 10-d]imidazole, 9-10-Phenanthraquinone, SBA-Pr-SO3H
  • Mohammad Mazloum, Ardakani *, Mehdi Maleki, Alireza Khoshroo Pages 350-358
    In the present paper, the electrochemical properties of magnetic iron oxide nanoparticles (Fe2O3 and Fe3O4) as highly sensitive sensors for the simultaneous determination of hydrazine and hydroxylamine was described. The electrochemical behavior of hydrazine and hydroxylamine was investigated using cyclic voltammetry, chronoamperometry and differential pulse voltammetry techniques. The results show that, at the modified electrode surface, the peaks of hydrazine and hydroxylamine oxidation were clearly separated from each other. Based on differential pulse voltammetry, the oxidation of hydrazine exhibited the dynamic range between 1.0- 1000.0 µM, and the detection limit (3σ) was 0.65 µM. These features will facilitate the determination of hydrazine and hydroxylamine in samples at a magnetic iron oxide modified electrode.
    Keywords: Electrocatalysis, Hydrazine, Hydroxylamine, Magnetic Nanoparticles, Modified Electrodes
  • Khawla Jameel Tahir *, Raja Al, Yasari Pages 359-365
    The present paper investigates a detailed study on the optical properties of PVA/Ag nanocomposite films. In this interest , PVA/Ag nanocomposites with different ways of study ,the first prepared film by reduction 0.2M of Ag+ ions in 2 gm of PVA and study the transmission , absorption coefficient, refractive index, extinction coefficient, reflection, real & imaginary part of the dielectric constant and the energy gap he results proved that the best values of the absorbency was within the range(350-500 )nm, as well as to both we noticed an increase of the refractive index , the extinction coefficient and reflectivity with increasing energy, the second step of research was by using Density Functional Theory (DFT) ,It was calculate spectrum absorption , intensity and energy gap for the same compound PVA/Ag, The cooperation of polyvinylalcohol (PVA) nanofibers with silver (Ag) nanoparticles (mean width 8nm) has been displayed utilizing thickness useful hypothesis (DFT) computations. The physical adsorption of PVA through the hydroxyl gathering, to the Ag,
    Keywords: Density Functional Theory (DFT), Optical Properties, Polyvinyl Alcohol, Silver
  • Sina Khanmohammadi, Mirzaagha Babazadeh * Pages 366-373
    The present research work describes an efficient method for facile synthesis of α-MnO2 nanorods by hydrothermal method and preparation of a series of polythiophene/manganese dioxide (PTh/MnO2) nanocomposites with various α-MnO2 ratios. These nanocomposites were fabricated by in-situ oxidative polymerization method using FeCl3 as oxidant, and characterized by Fourier transformed infrared (FT-IR), X-ray diffraction (XRD), energy-dispersive X-ray (EDX), thermogravimetric thermal analyses (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. FT-IR, EDX and XRD data showed that as-synthesized α-MnO2 nanorods has been definitely incorporated into the polymer matrix via in-situ core-shell polymerization. SEM and TEM pictures showed that the nanocomposites have rod-like morphology with the average diameter of 50-70 nm. TGA measurements showed that introducing α-MnO2 nanorods into PTh matrix, improve the thermal stability of nanocomposites in comparison with pure PTh. This employed method is very simple and inexpensive in comparison with methods applied by other researchers, and it can be easily applied industrially.
    Keywords: Nanocomposites, Polythiophene, ?-MnO2 nanorods, In-situ polymerization
  • Mohsen Amrollahi, Mohammad Taghi Ghaneian, Masoumeh Tabatabaee *, Mohammad Hassan Ehrampoush Pages 374-382
    An alomina-based nano adsorbent was prepared by modification of the external surface of γ-alumina (γ-Al2O3) nanoparticles with functional groups of a new Schiff base 4-[(2-hydroxy-3-methoxy-benzylidene)-amino]-5-methyl-2,4-dihydro-[1,2.4]triazole-3-thione] “L”. In order to the removal of Cr(VI) from aqueous solutions, we used the reaction of the sodium dodecyl sulfate coated nano-alumina with L solution for. This new modifying strategy significantly improve removal efficiency due to facilitate the accessibility of Cr ions to the activated sits. The surface morphology and chemistry of the adsorbent was characterized by SEM and FT-IR spectroscopy, respectively. Effect of most important parameters such as effect of pH value, contact time, adsorbent dosage, and initial Cr(VI) concentration on removal efficiency were investigated. In order to interpret the results Langmuir and Freundlich isotherm models were used. The results show that prepared absorbent significantly remove heavy metal ions from wastewater.The results show that prepared absorbent significantly remove heavy metal ions from wastewater.The results show that prepared absorbent significantly remove heavy metal ions from wastewater.
    Keywords: Removal of Cr(VI), Modified Alumina nanoparticles, Adsorption Isotherm
  • Javad SafaeiGhomi *, Soleiman PaymardSamani, Hossein ShahbaziAlavi Pages 383-390
    An efficient synthesis of (1H-tetrazole-5-yl) pyrazines is achieved by one pot multi- component coupling reaction of α-dicarbonyl compounds, 2,3-diaminomaleonitrile and sodium azide using MgFe2O4 nanoparticles as a robust catalyst under ultrasonic irradiation. This novel synthesic method using MgFe2O4 nanoparticles is easier, faster than that of using other nanoparicles. MgFe2O4 nanoparticles have been characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The attractive advantages of the present process are atom economy, wide range of products, high catalytic activity, excellent yields, short reaction times and simple operational procedures. Use of simple and readily available starting materials, experimental simplicity, applying the sono-chemical methodology as an efficient method and innocuous means of activation in synthetic chemistry are some properties of this protocol. The reusability of the MgFe2O4 nanoparticles catalyst was examined and it was found that product yields decreased to a small extent on each reuse. The possibility of performing multicomponent reactions with a green catalyst under ultrasonic irradiation plays a prominent role in green chemistry.
    Keywords: Pyrazines, MgFe2O4 nanoparticles, Ultrasonic irradiation, Heterogeneous catalysts
  • Masumeh Galini, Mehdi Salehi *, Mahdi Behzad Pages 391-403
    In this study, spinel-type cobalt oxide (Co3O4) and Co3-xDyxO4 (x = 0.04 and 0.05 molar ratio) nanoparticles were synthesized via combustion method at 700 °C. Crystallite nature, phase purity and thermal analysis of the prepared compounds were investigated by PXRD, FT-IR and TGA techniques. Structural analyses were performed by the FullProf program employing profile matching with constant scale factors. The results showed that the patterns had a main cubic structure with space group of Fd3m. The cell parameter data calculated by rietveld analysis showed that the cell parameters were nearly constant. The morphological and structural properties of the obtained materials were examined by FESEM and TEM images. Besides, the magnetic measurements of Co3O4 and Co3-xDyxO4 nanoparticles were performed by vibration sampling magnetometer (VSM). Coercivity (Hc) and remanent magnetization (Mr) were found to be reduced in Dy3+ doped Co3O4 while saturation magnetization (Ms) was increased moderately. The effect of dysprosium ion addition was also studied using cyclic voltammetry (CV) for the oxygen evolution reaction in an alkaline environment. The obtained data showed that the presence of Dy3+ exhibited a much higher oxygen evolution activity and lower over potential compared to Co3O4.
    Keywords: Catalytic activity, Nano Catalyst, Cobalt oxide, Magnetic properties, Dielectric properties
  • Morteza Shakeri Shamsi, Mehdi Ahmadi *, Mohammad Sabet Pages 404-407
    ZnO is a promising material suitable for variety of novel electronic applications including sensors, transistors, and solar cells. Intrinsic ZnO film has inferiority in terms of electronic properties, which has prompted researches and investigations on doped ZnO films in order to improve its electronic properties. In this work, aluminum (Al) doped ZnO (AZO) with various concentrations and undoped ZnO films were coated on glass substrates by a sol–gel spin coating technique. The samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Uv-Vis spectrometer and four point probe technique to investigate the structural, surface morphology, optical transmittance, and electronic properties of the thin films. The optical transmittances of these samples in the visible region are in the range of 85-95% and the SEM images showed the size of nanoparticles were decrease with doping. Also 2% Al doped ZnO thin films had a lowest resistivity of all the samples that prepared in this study.
    Keywords: Aluminum doped ZnO (AZO), Sol-Gel, Spin coating, Thin film
  • Gholamreza Nabiyouni *, Davood Ghanbari Pages 408-416
    Firstly nickel ferrite nanoparticles were synthesized via a simple precipitation method. Then mono-disperse platinum nanoparticles and NiFe2O4@TiO2/Pt nanocomposites were synthesized by a facile sol-gel procedure. The structure, phase and crystallite size of the magnetic and photo-catalyst products were characterized by X-ray diffraction pattern (XRD). The morphology and size of the nanostructures were surveyed by scanning electron microscopy (SEM). The purity of the samples was confirmed by Fourier transform infrared (FT-IR) spectroscopy. Vibrating sample magnetometer (VSM) illustrated that nickel ferrite nanoparticles have super paramagnetic behaviour. The photo catalytic behaviour of NiFe2O4@TiO2/Pt nanocomposites was approved using the fast degradation of two various azo dyes under visible and ultra violet light irradiation. The results show that nanocomposites have feasible magnetic feature for easy separation and effective photo catalytic properties for purification of organic dye contaminants. The antibacterial behaviour of NiFe2O4@TiO2/Pt nanocomposites was evaluated using degradation of E coli bacteria.
    Keywords: Photo-catalyst, Nanostructures, Nanocomposite, Magnetic
  • Hassan Karimi, Maleh *, Abdollah Fallah Shojaei, Fatemeh Karimi, Khalil Tabatabaeian, shahryar shakeri Pages 417-424
    In this study we suggested a new strategy for drug delivery of 6-thioguanine (6-TG) as a cancer drug by loading of this thiolic drug at a surface of Au nanoparticles. For this goal, we synthesized Au nanoparticle (Au/NPs) by reduction of tetrachloroauric (III) acid solutions by sodium borohydride and characterized Au/NPs by X-ray powder diffraction (XRD), dynamic light scattering (DLS), Ultraviolet–visible spectroscopy (UV-Vis) and transmission electron microscopy (TEM) methods. Results showed good distribution of synthesized Au nanoparticle with diameter ~ 5 nm. In the second step, we loaded 6-thioguanine with strong Au-S bond by addition of this drug to Au nanoparticle suspension and characterized it by UV-Vis method. Furthermore, Au nanoparticle loaded with 6-thioguanine was utilized as a new system against breast cancer cell line (MCF7). IC50 for free 6-thioguanine, unloaded Au nanoparticle and 6-thioguanine loaded Au nanoparticle (6-TG/Au/NPs) were >15.0, 80.0 and 3.5 μg/ml, respectively. The results obtained revealed high cytotoxicity effect of 6-TG/Au/NPs on breast cancer cell line.
    Keywords: 6-Thioguanine, Breast cancer cell line, Au nanoparticle, Drug Delivery