Description: Variable-Temperature Tip-Enhanced Raman Spectroscopy of Single-Molecule Fluctuations and Dynamics

This title appears in the Scientific Report : 2016

Variable-Temperature Tip-Enhanced Raman Spectroscopy of Single-Molecule Fluctuations and Dynamics

Structure, dynamics, and coupling involving single-molecules determine function in catalytic, electronic or biological systems. While vibrational spectroscopy provides insight into molecular structure, rapid fluctuations blur the molecular trajectory even in single-molecule spectroscopy, analogous t...

Personal Name(s):	Park, Kyoung-Duck
	Muller, Eric A. / Kravtsov, Vasily / Sass, Paul M. / Dreyer, Jens / Atkin, Joanna M. / Raschke, Markus B. (Corresponding author)
Contributing Institute:	GRS; GRS
Published in:	Nano letters, 16 (2016) 1, S. 479 - 487
Imprint:	Washington, DC ACS Publ. 2016
PubMed ID:	26679007
DOI:	10.1021/acs.nanolett.5b04135
Document Type:	Journal Article
Research Program:	Addenda
	Publikationsportal JuSER

Please use the identifier: http://dx.doi.org/10.1021/acs.nanolett.5b04135 in citations.

Structure, dynamics, and coupling involving single-molecules determine function in catalytic, electronic or biological systems. While vibrational spectroscopy provides insight into molecular structure, rapid fluctuations blur the molecular trajectory even in single-molecule spectroscopy, analogous to spatial averaging in measuring large ensembles. To gain insight into intramolecular coupling, substrate coupling, and dynamic processes, we use tip-enhanced Raman spectroscopy (TERS) at variable and cryogenic temperatures, to slow and control the motion of a single molecule. We resolve intrinsic line widths of individual normal modes, allowing detailed and quantitative investigation of the vibrational modes. From temperature dependent line narrowing and splitting, we quantify ultrafast vibrational dephasing, intramolecular coupling, and conformational heterogeneity. Through statistical correlation analysis of fluctuations of individual modes, we observe rotational motion and spectral fluctuations of the molecule. This work demonstrates single-molecule vibrational spectroscopy beyond chemical identification, opening the possibility for a complete picture of molecular motion ranging from femtoseconds to minutes.