Photoinduced conversion of silver nanospheres to nanoprisms.
30 Nov 2001-Science (American Association for the Advancement of Science)-Vol. 294, Iss: 5548, pp 1901-1903
TL;DR: This light-driven process results in a colloid with distinctive optical properties that directly relate to the nanoprism shape of the particles, which could be useful in developing multicolor diagnostic labels on the basis of nanoparticle composition and size but also of shape.
Abstract: A photoinduced method for converting large quantities of silver nanospheres into triangular nanoprisms is reported. The photo-process has been characterized by time-dependent ultraviolet-visible spectroscopy and transmission electron microscopy, allowing for the observation of several key intermediates in and characteristics of the conversion process. This light-driven process results in a colloid with distinctive optical properties that directly relate to the nanoprism shape of the particles. Theoretical calculations coupled with experimental observations allow for the assignment of the nanoprism plasmon bands and for the first identification of two distinct quadrupole plasmon resonances for a nanoparticle. Unlike the spherical particles they are derived from that Rayleigh light-scatter in the blue, these nanoprisms exhibit scattering in the red, which could be useful in developing multicolor diagnostic labels on the basis not only of nanoparticle composition and size but also of shape.
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TL;DR: In this paper, the authors describe recent progress in the theory of nanoparticle optical properties, particularly methods for solving Maxwell's equations for light scattering from particles of arbitrary shape in a complex environment.
Abstract: The optical properties of metal nanoparticles have long been of interest in physical chemistry, starting with Faraday's investigations of colloidal gold in the middle 1800s. More recently, new lithographic techniques as well as improvements to classical wet chemistry methods have made it possible to synthesize noble metal nanoparticles with a wide range of sizes, shapes, and dielectric environments. In this feature article, we describe recent progress in the theory of nanoparticle optical properties, particularly methods for solving Maxwell's equations for light scattering from particles of arbitrary shape in a complex environment. Included is a description of the qualitative features of dipole and quadrupole plasmon resonances for spherical particles; a discussion of analytical and numerical methods for calculating extinction and scattering cross-sections, local fields, and other optical properties for nonspherical particles; and a survey of applications to problems of recent interest involving triangula...
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TL;DR: The interest in nanoscale materials stems from the fact that new properties are acquired at this length scale and, equally important, that these properties are equally important.
Abstract: The interest in nanoscale materials stems from the fact that new properties are acquired at this length scale and, equally important, that these properties * To whom correspondence should be addressed. Phone, 404-8940292; fax, 404-894-0294; e-mail, mostafa.el-sayed@ chemistry.gatech.edu. † Case Western Reserve UniversitysMillis 2258. ‡ Phone, 216-368-5918; fax, 216-368-3006; e-mail, burda@case.edu. § Georgia Institute of Technology. 1025 Chem. Rev. 2005, 105, 1025−1102
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TL;DR: Monodisperse samples of silver nanocubes were synthesized in large quantities by reducing silver nitrate with ethylene glycol in the presence of poly(vinyl pyrrolidone) (PVP), characterized by a slightly truncated shape bounded by {100, {110}, and {111} facets.
Abstract: Monodisperse samples of silver nanocubes were synthesized in large quantities by reducing silver nitrate with ethylene glycol in the presence of poly(vinyl pyrrolidone) (PVP). These cubes were single crystals and were characterized by a slightly truncated shape bounded by {100}, {110}, and {111} facets. The presence of PVP and its molar ratio (in terms of repeating unit) relative to silver nitrate both played important roles in determining the geometric shape and size of the product. The silver cubes could serve as sacrificial templates to generate single-crystalline nanoboxes of gold: hollow polyhedra bounded by six {100} and eight {111} facets. Controlling the size, shape, and structure of metal nanoparticles is technologically important because of the strong correlation between these parameters and optical, electrical, and catalytic properties.
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TL;DR: This review describes recent fundamental spectroscopic studies that reveal key relationships governing the LSPR spectral location and its sensitivity to the local environment, including nanoparticle shape and size and introduces a new form of L SPR spectroscopy, involving the coupling between nanoparticle plasmon resonances and adsorbate molecular resonances.
Abstract: Localized surface plasmon resonance (LSPR) spectroscopy of metallic nanoparticles is a powerful technique for chemical and biological sensing experiments. Moreover, the LSPR is responsible for the electromagnetic-field enhancement that leads to surface-enhanced Raman scattering (SERS) and other surface-enhanced spectroscopic processes. This review describes recent fundamental spectroscopic studies that reveal key relationships governing the LSPR spectral location and its sensitivity to the local environment, including nanoparticle shape and size. We also describe studies on the distance dependence of the enhanced electromagnetic field and the relationship between the plasmon resonance and the Raman excitation energy. Lastly, we introduce a new form of LSPR spectroscopy, involving the coupling between nanoparticle plasmon resonances and adsorbate molecular resonances. The results from these fundamental studies guide the design of new sensing experiments, illustrated through applications in which researchers use both LSPR wavelength-shift sensing and SERS to detect molecules of chemical and biological relevance.
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Cites background from "Photoinduced conversion of silver n..."
...More refined synthetic approaches produce nanoparticles with less heterogeneity in shape and size and even higher refractive-index sensitivity (57, 69, 70)....
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TL;DR: A comprehensive review of current research activities that center on the shape-controlled synthesis of metal nanocrystals, including a brief introduction to nucleation and growth within the context of metal Nanocrystal synthesis, followed by a discussion of the possible shapes that aMetal nanocrystal might take under different conditions.
Abstract: Nanocrystals are fundamental to modern science and technology. Mastery over the shape of a nanocrystal enables control of its properties and enhancement of its usefulness for a given application. Our aim is to present a comprehensive review of current research activities that center on the shape-controlled synthesis of metal nanocrystals. We begin with a brief introduction to nucleation and growth within the context of metal nanocrystal synthesis, followed by a discussion of the possible shapes that a metal nanocrystal might take under different conditions. We then focus on a variety of experimental parameters that have been explored to manipulate the nucleation and growth of metal nanocrystals in solution-phase syntheses in an effort to generate specific shapes. We then elaborate on these approaches by selecting examples in which there is already reasonable understanding for the observed shape control or at least the protocols have proven to be reproducible and controllable. Finally, we highlight a number of applications that have been enabled and/or enhanced by the shape-controlled synthesis of metal nanocrystals. We conclude this article with personal perspectives on the directions toward which future research in this field might take.
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Book•
12 Jul 1985
TL;DR: In this paper, E.D. Palik and R.R. Potter, Basic Parameters for Measuring Optical Properties, and W.W.Hunter, Measurement of Optical Constants in the Vacuum Ultraviolet Spectral Region.
Abstract: VOLUME ONE: Determination of Optical Constants: E.D. Palik, Introductory Remarks. R.F. Potter, Basic Parameters for Measuring Optical Properties. D.Y. Smith, Dispersion Theory, Sum Rules, and Their Application to the Analysis of Optical Data. W.R. Hunter, Measurement of Optical Constants in the Vacuum Ultraviolet Spectral Region. D.E. Aspnes, The Accurate Determination of Optical Properties by Ellipsometry. J. Shamir, Interferometric Methods for the Determination of Thin-Film Parameters. P.A. Temple, Thin-Film Absorplance Measurements Using Laser Colorimetry. G.J. Simonis, Complex Index of Refraction Measurements of Near-Millimeter Wavelengths. B. Jensen, The Quantum Extension of the Drude--Zener Theory in Polar Semiconductors. D.W. Lynch, Interband Absorption--Mechanisms and Interpretation. S.S. Mitra, Optical Properties of Nonmetallic Solids for Photon Energies below the Fundamental Band Gap. Critiques--Metals: D.W. Lynch and W.R. Hunter, Comments of the Optical Constants of Metals and an Introduction to the Data for Several Metals. D.Y. Smith, E. Shiles, and M. Inokuti, The Optical Properties of Metallic Aluminum. Critiques--Semiconductors: E.D. Palik, Cadium Telluride (CdTe). E.D. Palik, Gallium Arsenide (GaAs). A. Borghesi and G. Guizzetti, Gallium Phosphide (GaP). R.F. Potter, Germanium (Ge). E.D. Palik and R.T. Holm, Indium Arsenide (InAs). R.T. Holm, Indium Antimonide (InSb). O.J. Glembocki and H. Piller, Indium Phosphide (InP). G. Bauer and H. Krenn, Lead Selenide (PbSe). G. Guizzetti and A. Borghesi, Lead Sulfide (PbS). G. Bauer and H. Krenn, Lead Telluride (PbTe). D.F. Edwards, Silicon (Si). H. Piller, Silicon (Amorphous) (-Si). W.J. Choyke and E.D. Palik, Silicon Carbide (SiC). E.D. Palik and A. Addamiano, Zinc Sulfide (ZnS). Critiques--Insulators: D.J. Treacy, Arsenic Selenide (As 2 gt Se 3 gt ). D.J. Treacy, Arsenic Sulfide (As 2 gt S 3 gt ). D.F. Edwards and H.R. Philipp, Cubic Carbon (Diamond). E.D. Palik and W.R. Hunter, Litium Fluoride (LiF). E.D. Palik, Lithium Niobote (LiNbO 3 gt ). E.D. Palik, Potassium Chloride (KCl). H.R. Philipp, Silicon Dioxide (SiO 2 gt ), Type ( (Crystalline). H.R. Philipp, Silicon Dioxide (SiO 2 gt ) (Glass). gt H.R. Philipp, Silicon Monoxide (SiO) (Noncrystalline). H.R. Philipp, Silicon Nitride (Si 3 gt N 4 gt ) (Noncrystalline). J.E. Eldridge and E.D. Palik, Sodium Chloride (NaCl). M.W. Ribarsky, Titanium Dioxide (TiO 2 gt ) (Rutile).
17,491 citations
"Photoinduced conversion of silver n..." refers methods in this paper
...Dielectric constant data are taken from (38)....
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...35S-labeled proteins were produced by in vitro transcription-translation (19) of 1 mg of pcDNA3-HuR (38), pcDNA Myc-hnRNP A1 (18), or pHybLex-HNS [made by subcloning the Eco RI–Xho I fragment of pcDNA3-HuR into the Eco RI–Xho I restriction sites of the pHybLex vector (Invitrogen)] plasmid....
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