Metal nanoshell

The metal nanoparticles have potential uses in technological and biomedical applications in particular silver ones are widely used due to their well-known antibacterial effects. In medicine silver nanoparticle (Ag-NPs) have found application as wound dressings, surgical instruments and bone substitute biomaterials [65]. 

By virtue of their strong antibacterial properties and low toxicity, Ag-NPs and their compounds have been studied for many years [66]. Meanwhile, studies conducted on Ag-NPs using different polymers have been reported these include the synthesis in poly(vinyl pyrrolidone) [67], poly(vinyl alcohol) [68], hyperbranched polyurethane [69] and aliphatic polyesters [70] to give discrete Ag-NPs. There are significant variations in the average sizes and shapes of the Ag-NPs when the polymers were used due to the different chemical structures and Ag/polymer interactions. 

Gampardelli et al. describe the production of biocompatible PLA with gold nanosphere composite particles of submicron size for photothermally induced release of rhodamine, used as a model drug [78,79]. 

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Hirsch LR, Gobin AM, Lowery AR, Tam F, Drezek RA, Halas NJ, West JL (2006) Metal nanoshells. Annals of Biomedical Engineering 34 15-22. 

Radloff C, Vaia RA, Brunton J, Bouwer GT, Ward VK (2005) Metal nanoshell assembly on a virus bioscaffold. Nano Lett 5 1187-1191... 

Wu, C., et al. (2005), Metal nanoshells as a contrast agent in near-infrared diffuse optical tomography, Opt. Commun., 253(1-3), 214-221. 

Fig. 6. Schematic view of the formation process of metallic nanoshells around organic micelles in aqueous solution. °> ...

Kirakosyan AS, Shahbazyan TV (2008) Vibrational modes of metal nanoshells and bimetallic core-shell nanoparticles. J Chem Phys 129 34708.1-34708.7... 

Westcott SL, Jackson JB, Radloff C, Halas NJ (2002) Relative contributions to the plasmon line shape of metal nanoshells. Phys Rev B 66 155431... 

Zhang P, Guo Y (2009) Surface-enhanced Raman scattering inside metal nanoshells. J Am ChemSoc 131 3808-3809... 

R. D. Averitt N. J. Halas, Surface enhanced Raman scattering in the near infrared using metal nanoshell substrates./. Chem. Phys. 1999, 333, 4729-4735. 

Figure 6.5 Energy level diagram for plasmon hybridization in a metal nanoshell by combination of the plasmons for a sphere and a cavity. The two nanoshell plasmons are symmetrically and antisymmetrically coupled and have energies given by Eq. (6.6).

Prodan, E. and Nordlander, P. (2003) Structural lunaliilily of the plasmon resonances in metallic nanoshells. Nano Letters, 3, 543-547. 

Bardhan, R., Grady, N.K., Ali, T., and Halas, N.J. (2010) Metallic nanoshells with semiconductor cores optical characteristics modified by core medium properties. ACS Nano, 4, 6169-6179. 

Halas, N. J. Playing with plasmons. Tuning the optical resonant properties of metallic nanoshells. MRS Bulletin 2005, 30, 362-367. 

Nordlander, P. Prodan, E. Electronic structure and optical properties of metallic nanoshells. In Plasmonics Metallic Nanostructures and their Optical Properties, Halas,... 

N. J. Halas and R. K. Bradley, Partial coverage metal nanoshells and method of making same. Patent... 

Among metallic nanoparticles which have recently attracted considerable attention, a particularly interesting structure is the metallic nanoshell which consists of a metallic layer grown over a solid dielectric core [34,57,68-76]. 

Lombardini, R., Acevedo, R., Halas, N. J., and Johnson, B. R. (2010) Plasmonic enhancement of Raman optical activity in molecules near metal nanoshells Theoretical comparison of circular polarization methods,/ Phys. Chem. C, 114, 7390-7400. 

Alpeggiani, E, D Agostino, S., and Andreani, L. C. (2012) Surface plasmons and strong light-matter coupling in metallic nanoshells, Phys. Rev. B, 86, 035421-1/14. 

Hale, G. D., Jackson, J. B., Shmakova, 0. E., Lee, T. R., and Halas, N. J. [2001] Enhancing the active lifetime of luminescent semiconducting polymers via doping with metal nanoshells, Appl Phys. Lett., 78,1502-1504. 

It must be mentioned that a plasmon hybridization model was first developed by Nordlander and Halas in order to explain the LSPR resonances properties of metal nanoshell structures [48]. In a later section, we shall show the analogy between the hybridization in the two-particle dimer with that of a metal nanoshell. 

Jain, P. K., and El-Sayed, M. A. (2007) Surface plasmon resonance sensitivity of metal nanostructures Physical basis and universal scaling in metal nanoshells,/. Phys. Chem. C, 111, 17451-17454. 

Extension of Photocatalytic Reduction Method, and the Post Chemical Reduction Treatment to Form Metal Nanoshell Structure... 

Perhaps, it becomes difficult to deposit gold (Au) NPs directly, as Au shell, on the surface of poly(DCHD) core by means of the photocatalytic reduction method [60], since the redox potential of [AuCU] , precusor of Au, is 1.002 mV vs SHE. This value is close to the redox potential of water given by (2) as well as VB for PDA as shown in Fig. 12. In addition, [AuC ] may absorb some VIS light, which is also undesirable in the present preparation procedure. However, already-deposited Ag NPs on poly(DCHD) core can be regarded as both a catalyst and a substrate for electroless plating with other kinds of metals. Thus, we could prepare metal nanoshell structure by means of post-chemical reduction treatment. 

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