Ultrasmall hollow gold-silver nanoshells with extinctions strongly red-shifted to the near-infrared

ACS Appl Mater Interfaces. 2011 Sep;3(9):3616-24. doi: 10.1021/am2008322. Epub 2011 Aug 17.

Abstract

Hollow gold-silver nanoshells having systematically varying sizes between 40 and 100 nm were prepared. These particles consist of a hollow spherical silver shell surrounded by a thin gold layer. By varying the volume of the gold stock solution added to suspensions of small silver-core templates, we tailored the hollow gold-silver nanoshells to possess strong tunable optical extinctions that range from the visible to the near-IR spectral regions, with extinctions routinely centered at ∼950 nm. The size and morphology of these core/shell nanoparticles were characterized by dynamic light scattering (DLS), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). Separately, X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) were used for measuring their elemental composition; UV-vis spectroscopy was used to evaluate their optical properties. Given their relatively small size compared to other nanoparticles that absorb strongly at near IR wavelengths, these easy-to-synthesize particles should find use in applications that require ultrasmall nanoparticles with extinctions comfortably beyond visible wavelengths (e.g., medicinal therapies, diagnostic imaging, nanofluidics, and display technologies).

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Gold / chemistry*
  • Nanoshells / chemistry*
  • Nanoshells / ultrastructure
  • Particle Size
  • Photoelectron Spectroscopy
  • Silver / chemistry*
  • Spectrophotometry, Ultraviolet
  • Spectroscopy, Near-Infrared
  • X-Ray Diffraction

Substances

  • Silver
  • Gold