Raman properties of gold nanoparticle-decorated individual carbon nanotubes

Single-wall carbon nanotubes decorated by gold nanoparticles with sizes of a few tens of nanometers were investigated by confocal Raman microscopy. It was found that individual nanoparticles impart a sizable Raman enhancement exceeding one order of magnitude, without appreciably interfering with polarization dependent Raman measurements. By contrast, cavity effects within small nanoparticle agglomerates resulted in a 20-fold stronger enhancement and significant distortions of the polarization characteristic. (c) 2007 American Institute of Physics.