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High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
Published on: June 28, 2016
Heterodyne-detected dispersed vibrational echo spectroscopy
Kevin C Jones1, Ziad Ganim, Andrei Tokmakoff
1Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, 6-213 Cambridge, Massachusetts 02139, USA.
The Journal of Physical Chemistry. A
|November 27, 2009
Summary
We introduce heterodyned dispersed vibrational echo spectroscopy (HDVE), a powerful ultrafast technique for biophysical studies. HDVE offers high sensitivity and single-shot capabilities for detailed molecular analysis.
Area of Science:
- Biophysics
- Spectroscopy
- Physical Chemistry
Background:
- Ultrafast spectroscopy is crucial for characterizing molecular dynamics.
- Existing techniques may lack sensitivity or single-shot capabilities for complex systems.
- Accurate characterization of nonlinear optical signals is essential for probing molecular structure and dynamics.
Purpose of the Study:
- To develop and validate heterodyned dispersed vibrational echo spectroscopy (HDVE).
- To demonstrate HDVE's utility in biophysical applications, particularly protein spectroscopy.
- To compare different methods for extracting HDVE phase and amplitude spectra.
Main Methods:
- Development of heterodyned dispersed vibrational echo spectroscopy (HDVE).
- Comparison of four spectral extraction techniques: Fourier transform spectral interferometry, phase modulation spectral interferometry, and combined schemes.
- Application to protein amide I spectroscopy, including ubiquitin and insulin.
Main Results:
- HDVE successfully characterizes real and imaginary components of third-order nonlinear signals with high sensitivity.
- Single-shot spectra and melting curves of ubiquitin were acquired.
- Concentration-dependent spectra of insulin were obtained, enabling binding constant determination.
Conclusions:
- HDVE is a robust technique for biophysical applications, offering enhanced sensitivity and single-shot capabilities.
- The developed methods allow for detailed spectral analysis, including dispersed pump-probe and dispersed vibrational echo spectra.
- HDVE is particularly promising for transient experiments, irreversible reactions, and low-concentration studies.
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