Distinguishable behavior of multiple and individual rhodamine-6G molecules on spherical Ag nanoparticles examined via time dependence of the SERS spectra
Article first published online: 16 JUL 2012
Copyright © 2012 John Wiley & Sons, Ltd.
Journal of Raman Spectroscopy
Volume 43, Issue 12, pages 1905–1912, December 2012
How to Cite
Luo, Z., Hunter Woodward, W. and Castleman, A. W. (2012), Distinguishable behavior of multiple and individual rhodamine-6G molecules on spherical Ag nanoparticles examined via time dependence of the SERS spectra. J. Raman Spectrosc., 43: 1905–1912. doi: 10.1002/jrs.4107
- Issue published online: 14 DEC 2012
- Article first published online: 16 JUL 2012
- Manuscript Accepted: 15 APR 2012
- Manuscript Revised: 31 MAR 2012
- Manuscript Received: 26 SEP 2011
- spherical Ag nanoparticles;
- time dependence
We report a surface-enhanced Raman spectroscopy (SERS) investigation to probe the adsorption and dynamic behavior of rhodamine 6 G (Rh6G) molecules on spherical Ag nanoparticles which were produced via laser ablation in liquid. Assembly of the colloidal Ag nanoparticles on a cover glass was used to work as SERS substrates on which high-quality SERS spectra of Rh6G were obtained with interesting time dependence when using low and ultralow concentrations, respectively. The variation of SERS spectra over time was identified with the adsorption behavior of multiple and individual molecules on the Ag nanoparticles. Analysis indicates that the adsorbed Rh6G molecules can desorb away from the initial locations on the substrate under continuous laser excitation; simultaneously, some individual molecules can move and become trapped in the gap between the aggregated Ag nanoparticles. These investigations help to clarify the origins of forming ‘hot-spots’ which host probe molecules and hence improve the understanding of mechanisms for single-molecule SERS spectroscopy. Copyright © 2012 John Wiley & Sons, Ltd.