Silver nanocrystal-modified silicon nanowires as substrates for surface-enhanced Raman and hyper-Raman scattering.
Metal catalyzed, CVD-grown silicon nanowires decorated by chemical assembly of closely spaced Ag nanocrystals were modified with the well-known "silver mirror" reaction and investigated as substrates for surface-enhanced Raman (SERS) and hyper-Raman (SEHRS) spectroscopy. Four chromophores were examined: Rhodamine 6G, crystal violet, a cyanine dye, and a cationic donor-acceptor substituted stilbene. After soaking the substrates overnight in 10(-4) M aqueous chromophore solutions, all four chromophores gave good-quality SERS spectra in < or =60 s using <1 microW of 458-nm cw laser power, and SEHRS spectra are obtained in < or =120 s using <1 mW of mode-locked 916-nm laser power. Results from this substrate are compared with those on colloidal silver nanoparticles deposited as a film, as well as surfaces grown by the silver mirror reaction.
Leng
Weinan
W
School of Natural Sciences, University of California, Merced, P.O. Box 2039, Merced, CA 95340, USA.
Yasseri
Amir A
AA
Sharma
Shashank
S
Li
Zhiyong
Z
Woo
Han Young
HY
Vak
Doojin
D
Bazan
Guillermo C
GC
Kelley
Anne Myers
AM
D008855:Microscopy, Electron, Scanning; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure*; D012825:Silicon / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
D012834:Silver; D012825:Silicon