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Nanoparticle Arrays (nanoparticle + array)

Distribution by Scientific Domains
Polymers and Materials Science55%
Physics and Astronomy22%
Chemistry22%

Kinds of Nanoparticle Arrays

  • gold nanoparticle array
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    Selected Abstracts

    Preparation of Nanogapped Gold Nanoparticle Array for DNA Detection

    ELECTROANALYSIS, Issue 4 2008
    Shiho Tokonami
    Abstract A novel DNA detection technique using a gold nanoparticle array film electrode has been reported here. The gold nanoparticles molecularly linked with binder molecule (1,10-decanedithiol) were separated 1.3,nm from each other, and the DNA conductivity change from single to double strand was measured by monitoring a voltage drop across the particles, between which a probe of a 12-mer oligonucleotide was immobilized. In adding a complementary oligonucleotide on the nanoparticle film chip, an immediate decrease in the film resistance (ca. 1.4 ,) due to a hybridization event occurred in a reproducible manner with this simple setup. In the paper, we have an interest in the primary sensing properties; effect of the film resistance on the sensor response, dependence of the resistance change on the DNA concentration, and the performance of the system for DNA detection including single nucleotide polymorphisms were described. [source]

    Antireflective Nanoparticle Arrays Enhance the Efficiency of Silicon Solar Cells

    ADVANCED FUNCTIONAL MATERIALS, Issue 18 2010
    Dehui Wan
    Abstract In this study, the phenomenon of light trapping in Si solar cells coated with metal (Au) and dielectric (TiO2, SiO2) nanoparticles (NPs) is systematically investigated. In contrast to previous reports, herein it is proposed that the photocurrent enhancement of solar cells should be attributed to the limited antireflection ability of the Au NP arrays. In other words, the Au NP arrays might not enhance the absorption of the active layer in cells when no light is reflected from the air,substrate interface. Therefore, the Au NPs are replaced with dielectric NPs, which possess lower extinction coefficients, and then the antireflection property of the TiO2 NP arrays is optimized. A simple, rapid, and cheap solution-based method is used to prepare close-packed TiO2 NP films on Si solar cells; these devices exhibit a uniform and remarkable increase (ca. 30%) in their photocurrents. To the best of the authors' knowledge, this uniform photocurrent enhancement is greater than those obtained from previously reported metal and dielectric NP,enhanced Si wafer-based solar cells. [source]

    Formation of Gold and Silver Nanoparticle Arrays and Thin Shells on Mesostructured Silica Nanofibers,

    ADVANCED FUNCTIONAL MATERIALS, Issue 16 2007
    S. Zhang
    Abstract Mesostructured silica nanofibers synthesized in high yields with cetyltrimethylammonium bromide as the structure-directing agent in HBr solutions are used as templates for the assembly of Au and Ag nanoparticles and the formation of thin Au shells along the fiber axis. Presynthesized spherical Au and Ag nanoparticles are adsorbed in varying amounts onto the silica nanofibers through bifunctional linking molecules. Nonspherical Au nanoparticles with sharp tips are synthesized on the nanofibers through a seed-mediated growth approach. The number density of nonspherical Au nanoparticles is controlled by varying the amount of seeded nanofibers relative to the amount of supplied Au precursor. This seed-mediated growth is further used to form continuous Au shells around the silica nanofibers. Both the Au- and Ag-nanoparticle/silica-nanofiber hybrid nanostructures and silica/Au core/shell fibers exhibit extinction spectra that are distinct from the spectra of Au and Ag nanoparticles in solution, indicating the presence of new surface plasmon resonance modes in the silica/Au core/shell fibers and surface plasmon coupling between closely spaced metal nanoparticles assembled on silica nanofibers. Spherical Au- and Ag-nanoparticle/silica-nanofiber hybrid nanostructures are further used as substrates for surface-enhanced Raman spectroscopy, and the enhancement factors of the Raman signals obtained on the Ag-nanoparticle/silica-nanofiber hybrid nanostructures are 2,×,105 for 4-mercaptobenzoic acid and 4-mercaptophenol and 7,×,107 for rhodamine,B isothiocyanate. These hybrid nanostructures are therefore potentially useful for ultrasensitive chemical and biological sensing by using molecular vibrational signatures. [source]

    Nanoparticle Arrays on Surfaces Fabricated Using Anodic Alumina Films as Templates,

    ADVANCED FUNCTIONAL MATERIALS, Issue 5 2003
    M.S. Sander
    Abstract High density nanoparticle arrays on surfaces have been created using a template-assisted approach. Templates were produced by evaporating aluminum onto substrates and subsequently anodizing the aluminum to produce nanoporous alumina films. The resulting templates have a narrow distribution of pore sizes tunable from ,,25 to ,,70 nm. To demonstrate the flexibility of this approach for producing nanoparticle arrays on various substrates, templates have been fabricated on silicon oxide, silicon, and gold surfaces. In all cases, a final chemical etching step yielded pores that extended completely through the template to the underlying substrate. Because the templates remain in intimate contact with the substrate throughout processing, they may be used with either vacuum-based or wet chemical deposition methods to direct the deposition of nanoparticles onto the underlying substrates. Here we have produced gold nanodot arrays using evaporation and gold nanorod arrays by electrodeposition. In each case, the diameter and height of the nanoparticles can be controlled using the confining dimensions of the templates, resulting in high density (,,1010,cm,2) arrays of nanoparticles over large areas (>,1 cm2). [source]

    DNA-Wrapped Single Walled Carbon Nanotubes as Rigid Templates for Assembling Linear Gold Nanoparticle Arrays,

    ADVANCED MATERIALS, Issue 11 2007
    X. Han
    Nanotube templates assembly: Water-soluble conjugates between gold nanoparticles and DNA-wrapped single-walled carbon nanotubes (SWNTs), as shown in the figure, are constructed based on a self-assembly strategy that does not require any chemical modifications to the sidewalls of the SWNTs, which minimizes the possibility of changes to their structure and properties. The success of assembling Au nanoparticles (AuNPs) onto SWNTs paves a way for further decoration of AuNPs on SWNTs to achieve multifunctionalities. [source]

    One-Dimensional Gold Nanoparticle Arrays by Electrostatically Directed Organization Using Polypeptide Self-Assembly,

    ANGEWANDTE CHEMIE, Issue 38 2009
    Nikhil Sharma
    In Reih und Glied: Die einzigartige molekulare Architektur eines selbstorganisierten Polypeptidtemplats ermöglicht das elektrostatische Abscheiden von Nanopartikeln mit einheitlichem Partikelabstand. Die hierarchisch ablaufende Selbstorganisation des Polypeptids führt zu einer periodischen Anordnung geladener Flecken entlang der Fibrillenarchitektur (siehe Bild). [source]

    Metallic nanoparticle array on GaN by microsphere lithography

    PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue S2 2009
    Giuseppe Y. Mak
    Abstract The optical characteristics of GaN blue-light (peak wavelength at 440 nm) light-emitting diode (LED) under the effect of localized surface plasmon (LSP) have been studied. Hexagonal arrays of triangular metallic nanoparticles deposited through a self-assembled silica microsphere mask have been fabricated using vertical deposition. By comparing the PL spectra of samples coated with Au, Al and Ag nanoparticles, it is found that Ag nanoparticles offer the most pronounced PL enhancement. The resonance wavelength was determined from optical transmission and verified by theoretical calculations. These results provide a cost-effective solution for improving the efficiency of LEDs. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Spatially Resolved Mapping of Polarization Switching Behavior in Nanoscale Ferroelectrics,

    ADVANCED MATERIALS, Issue 1 2008
    J. Rodriguez
    The spatial variability of polarization switching in ferroelectric lead zirconate-titanate nanoparticle arrays and within a single sub-100 nanometer nanoparticle is investigated by using switching spectroscopy piezoresponse force microscopy. Strong variations of switching properties within a single nanoparticle are observed and attributed to polarization pinning by geometric effects and interfacial dislocations. The spatial distributions of imprint bias and the thickness of the frozen polarization layer within the nanoparticle are reconstructed. [source]

    Plasmonic modes of gold nano-particle arrays on thin gold films

    PHYSICA STATUS SOLIDI - RAPID RESEARCH LETTERS, Issue 10 2010
    A. Hohenau
    Abstract Regular arrays of metal nanoparticles on metal films have tuneable optical resonances that can be applied for surface enhanced Raman scattering or biosensing. With the aim of developing more surface selective geometries we investigate regular gold nanoparticle arrays on 25 nm thick gold films, which allow to excite asymmetric surface plasmon modes featuring a much better field confinement compared to the symmetric modes used in conventional surface plasmon resonance setups. By optical extinction spectroscopy we identify the plasmonic modes sustained by our structures. Furthermore, the role of thermal treatment of the metal structures is investigated, revealing the role of modifications in the crystalline structure of gold on the optical properties. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]