Ag shell-Au satellite hetero-nanostructure for ultra-sensitive, reproducible, and homogeneous NIR SERS activity

ACS Appl Mater Interfaces. 2014 Aug 13;6(15):11859-63. doi: 10.1021/am503675x. Epub 2014 Aug 4.

Abstract

It is critical to create isotropic hot spots in developing a reproducible, homogeneous, and ultrasensitive SERS probe. Here, an Ag shell-Au satellite (Ag-Au SS) nanostructure composed of an Ag shell and surrounding Au nanoparticles was developed as a near-IR active SERS probe. The heterometallic shell-satellite structure based SERS probe produced intense and uniform SERS signals (SERS enhancement factor ∼1.4 × 10(6) with 11% relative standard deviation) with high detectability (100% under current measurement condition) by 785 nm photoexcitation. This signal enhancement was independent of the laser polarizations, which reflects the isotropic feature of the SERS activity of Ag-Au SS from the three-dimensional (3D) distribution of SERS hot spots between the shell and the surrounding satellite particles. The Ag-Au SS nanostructure shows a great potential as a reproducible and quantifiable NIR SERS probe for in vivo targets.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Gold / chemistry*
  • Imaging, Three-Dimensional
  • Light
  • Metal Nanoparticles / chemistry
  • Metals / chemistry
  • Mice
  • Microscopy, Electron, Scanning
  • Microscopy, Electron, Transmission
  • Nanostructures / chemistry
  • Nanotechnology / methods*
  • Particle Size
  • Reproducibility of Results
  • Scattering, Radiation
  • Silver / chemistry*
  • Spectroscopy, Near-Infrared*
  • Spectrum Analysis, Raman
  • Surface Properties

Substances

  • Metals
  • Silver
  • Gold