Chain-length-dependent vibrational resonances in alkanethiol self-assembled monolayers observed on plasmonic nanoparticle substrates.
Alkanethiol self-assembled monolayers (SAMs) on gold exhibit a series of sharp resonances in their surface-enhanced Raman spectrum that depend dramatically on carbon chain length. This unusual behavior suggests a coupling of the gold-sulfur bond stretch with the longitudinal acoustic, "accordion", vibrations of the molecular alkane chain. A simple model of a one-dimensional chain attached to a surface quantitatively reproduces these previously unreported experimental observations in this important nanomaterial system.
Levin
Carly S
CS
Department of Chemistry and the Laboratory for Nanophotonics, Rice University, 6100 Main Street, Houston, Texas 77005, USA.
Janesko
Benjamin G
BG
Bardhan
Rizia
R
Scuseria
Gustavo E
GE
Hartgerink
Jeffrey D
JD
Halas
Naomi J
NJ
D000473:Alkanes / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D008422:Materials Testing; D053758:Nanoparticles / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013059:Spectrum Analysis, Raman / Q000379:methods; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013499:Surface Properties; D014732:Vibration
D000473:Alkanes; D013438:Sulfhydryl Compounds; D002244:Carbon; D006046:Gold