Variable-Temperature Tip-Enhanced Raman Spectroscopy of Single-Molecule Fluctuations and Dynamics.
Nano Lett
; 16(1): 479-87, 2016 Jan 13.
Article
en En
| MEDLINE
| ID: mdl-26679007
ABSTRACT
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.
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1
Bases de datos:
MEDLINE
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Nano Lett
Año:
2016
Tipo del documento:
Article
País de afiliación:
Estados Unidos