Subdiffraction limited, remote excitation of surface enhanced Raman scattering

Nano Lett. 2009 Mar;9(3):995-1001. doi: 10.1021/nl8030696.

Abstract

We demonstrate that focused laser excitation at the end of silver nanowires of 50-150 nm diameter excites SERS hot-spots at points of nanoparticle adsorption many micrometers along the wire due to the plasmon waveguide effect. The total SERS intensity detected at the hot-spots following wire-end excitation correlates with the known wavelength, polarization, and distance dependences of surface plasmon polariton (SPP) propagation in nanowires. The SERS spectra obtained at the hot-spots following wire-end excitation show very little background compared to when excitation occurs directly at the hot-spot, suggesting that a much smaller SERS excitation volume is achieved by remote, waveguide excitation. The ability to transfer SERS excitation over several micrometers, through a structure with a subdiffraction limit diameter, is discussed with respect to potential high-resolution SERS imaging applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Electromagnetic Fields
  • Light
  • Microscopy, Scanning Probe / methods
  • Nanoparticles / chemistry
  • Nanotubes, Carbon / chemistry
  • Nanowires / chemistry
  • Phenols / chemistry
  • Spectrum Analysis, Raman / methods*
  • Sulfhydryl Compounds / chemistry
  • Surface Properties

Substances

  • Nanotubes, Carbon
  • Phenols
  • Sulfhydryl Compounds
  • thiophenol