A frequency domain existence proof of single-molecule surface-enhanced Raman spectroscopy

Jon A. Dieringer, Robert B. Lettan, Karl A Scheidt, Richard P Van Duyne*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

423 Scopus citations

Abstract

The existence of single-molecule surface-enhanced Raman spectroscopy (SMSERS) is proven by employing a frequency-domain approach. This is demonstrated using two isotopologues of Rhodamine 6G that offer unique vibrational signatures. When an average of one molecule was adsorbed per silver nanoparticle, only one isotopologue was typically observed under dry N 2 environment. Additionally, the distribution of vibrational frequencies hidden under the ensemble average is revealed by examining the single-molecule spectra. Correlation with transmission electron microscopy reveals that SMSERS active aggregates are composed of multiple randomly sized and shaped nanoparticles. At higher coverage and in a humid environment, adsorbate interchange was detected. Using 2D cross correlation, vibrational modes from different isotopologues were anti-correlated, indicating that the dynamic behavior was from multiple molecules competing for a single hot spot. This allows hot-spot diffusion to be directly observed without analyzing the peak intensity fluctuations.

Original languageEnglish (US)
Pages (from-to)16249-16256
Number of pages8
JournalJournal of the American Chemical Society
Volume129
Issue number51
DOIs
StatePublished - Dec 26 2007

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

Fingerprint Dive into the research topics of 'A frequency domain existence proof of single-molecule surface-enhanced Raman spectroscopy'. Together they form a unique fingerprint.

Cite this