ABSTRACTColloidal Au/Ag nanoparticles can be controllably assembled on anodic aluminum oxide (AAO) surfaces; monolayer coating on the membrane on AAO with smaller pores, or a nano-net arrangement along the edges of AAO with larger pores. The supported Au and Ag nanoparticles on the AAO membranes are closely packed and exhibited localized surface plasmon resonance (LSPR). Thus AAO membrane coated with Au or Ag nanoparticles is a highly surface-enhanced Raman scattering (SERS) active substrate. High quality SERS spectra were obtained using fullerene molecules C60 & C70 as the probe molecules and the filtered Au nanoparticles as the substrate. Furthermore, new SERS systems were obtained from Au nanoparticles assembled into the pores of AAO-supported fullerene nano-tubes, and the C60/C70 nano-tube arrays loaded with Au nanoparticles. The new SERS systems made use of the contributions from AAO, the LSPR of the Au nanoparticles, and a uniform assembly of the probe molecules in the nanostructures. These approaches have also been applied to small organic molecule systems using Ag nanoparticles.
Stamping surface-enhanced Raman spectroscopy for label-free, multiplexed, molecular sensing and imaging
