Download or read book Fabrication, Characterization and Optical Properties of Three-dimensional Colloidal Gold Nanostructures written by Christopher James Addison and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 3-Dimensional nanostructures were constructed through the alternate immersion of aderivatized glass slide in solutions of propanedithiol and gold nanoparticles. The size andshape of the surface features could be controlled based on the number of nanoparticledepositions. Characterization of the substrates was performed using W-Visspectroscopy and atomic force microscopy. The multilayer nanoparticle substrates wereexamined for their suitability in surface-enhanced Raman scattering (SERS) by obtainingthe SERS spectrum of oxazine-720 on the substrates. A dramatic increase in the SERSsignal is noted with increasing nanoparticle layers and reaches a maximum for 11nanoparticle-layer depositions. The enhancement is attributed to the underlying surfacemorphology: Surface features on the order of 40 nm in size yield the greatest SERSenhancement due to surface plasmon (SP) excitation. The non-linear optical properties of colloidal nanostructures were examined using secondharmonic generation (SHG). A pronounced second harmonic emission was noted for 13nanoparticle layers and was attributed to SP excitation to yield surface-enhanced SHG. The self-assembly of gold nanorods to form 3-dimensional nanostructures was examined. While the self-assembly was not successful, the aggregated gold nanorods exhibited alarge SERS enhancement. This suggests that the incorporation of gold nanorods intoSERS substrates is a viable avenue for future research.