Metallic nanostructures

I 5 Molecular Cels for Controlled Formation of Micro-/Nano-Structures 

Gold Urea amphiphile (1) Water, acetone Gelator [37] 

Gold Amino acid-based (5) Water Gelator [43] 

Silver Oligomeric amines + stearic/ eicosanoic acid Water NaBH4 [39] 

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To demonstrate the utilities of salt inclusion, we review the selected zeoUte-like transition-metal-containing open frameworks (TMCOFs) and then describe the structures of non-centrosymmetric solids (NCSs) and, finally, report crystalline solids containing a periodic array of transition metal nanostructures. In particular, we will address the issues concerning the role that molten salt has in... 

Solids Containing Periodic Arrays of Transition-metal Nanostructures... 

STM-Raman spectroscopy utilizes the effect that Raman scattering is enhanced for a molecule in the vicinity of a metal nanostructure. This enhancement effect is generally called surface-enhanced Raman scattering (SERS). When a sharp scanning probe, such as a tunneling tip for STM, is used as a metal nanostructure to enhance Raman intensity, it is called tip-enhanced Raman scattering (TERS). The concept of STM combined with Raman spectroscopy is presented in Figure 1.1. 

Solid SERS Substrates Based on Metallic Nanostructures... 

Figure 3. Various type of SERS active metallic nanostructures (a) metal-island films (b) metal-coated nanospheres (semi-nanoshells) (c) metal-coated random nanostructures and (d) polymer coatings embedded with metal nanoparticles. Inset An SEM image of silver-coated polystyrene spheres.

The development of dependable SERS active metallic nanostructures has spurred renewed interest in Raman scattering as a practical analytical tool in... 

Localized plasmon resonance on noble metal nanostructures Noble metal nanostructures exhibit a strong UV visible extinction band with its peak position affected by the dielectric constant and thickness of the material surrounding the nanostructures 7,11 13... 

Fu Y, Lakowicz JR (2009) Modification of single molecule fluorescence near metallic nanostructures. Laser Photon Rev 3 221-232... 

High photostability and intense fluorescence signals are always criteria for making better DDSNs. To obtain a better DDSN, various nanostructures for fluorescence enhancements have been developed. The coexistence of a noble metal nanostructure with fluorophores can enhance both the fluorescence intensity and photostability... 

J.M. Montgomery, T.-W. Lee, S.K. Gray, Theory and modelling of light interactions with metallic nanostructures, J. Phys. Condens. Matter, 20, 1-11 (2008). 

Hayazawa, N., Ichimura, T., Hashimoto, M., Inouye, Y., and Kawata, S. 2004a. Amphhcation of coherent anh-Stokes Raman scattering by a metallic nanostructure for a high resolution vibration microscopy. J. Appl. Phys. 95 2676-81. 

Murphy CJ, Sau TK, Gole A, Orendorff CJ (2005) Surfactant-directed synthesis and optical properties of one-dimensional plasmonic metallic nanostructures. MRS Bull 30 349-355... 

Exploitation of Near-Field Enhancement in Metal Nanostructures. 193... 

Similar to zero-dimensional metal nanoparticles, most of the work on one-dimensional metal nanostructures focuses almost exclusively on gold nanorods. The high interest in anisometric gold nanoclusters arises from their unique optical and electronic properties that can be easily tuned through small changes in size, structure (e.g., the position, width, and intensity of the absorption band due to the longitudinal surface plasmon resonance is strongly influenced by the shell as well as the aspect ratio of the nanorods), shape (e.g., needle, round capped cylinder, or dog bone), and the inter-particle distance [157]. 

Readers interested in more specific details about synthesis strategies, mechanisms of nanorod formation, characterization, or factors influencing the morphology of noble metal nanorods are referred to a comprehensive review by Sau and Rogach [185]. Reviews by Kijima and Zhang et al. will provide additional, detailed information on the synthesis of other one-dimensional metal nanostructures (including nanowires and nanotubes) [186, 187]. 

Sun, Y., Mayers, B. Xia, Y. Metal nanostructures with hollow interiors. Adv. Mater. (Weinheim,... 

Lopes, W. A. Jaeger, H. M. Hierarchical self-assembly of metal nanostructures on diblock copolymer scaffolds. Nature (London) 414, 735-8 (2001). 

The extremely small cross sections for conventional Raman scattering, typically 10 111 to 10-25 cm2/molecule has in the past precluded the use of this technique for single-molecule detection and identification. Until recently, optical trace detection with single molecule sensitivity has been achieved mainly using laser-induced fluorescence [14], The fluorescence method provides ultrahigh sensitivity, but the amount of molecular information, particularly at room temperature, is very limited. Therefore, about 50 years after the discovery of the Raman effect, the novel phenomenon of dramatic Raman signal enhancement from molecules assembled on metallic nanostructures, known as surface-enhanced Raman spectroscopy or SERS, has led to ultrasensitive single-molecule detection. 

Recently, a profound interest in studies of properties of granulated metals, structures constituted by metallic nanoparticles, has been aroused. Problems associated with the application of these structures in the development of new nanoelectronic devices [1], devices for ultrahigh-density magnetic recording [2], new functional coatings [3], and high-efficiency solid-state catalysts [4] are widely discussed in the literature. This chapter is concerned with catalytic properties of metallic nanostructures. 

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