Stimulated Raman Excited Fluorescence Spectroscopy and Imaging

Area of Science:

• Optics and Photonics
• Spectroscopy
• Biophysics

Background:

• Fluorescence detection offers high sensitivity but limited chemical information.
• Raman spectroscopy provides chemical specificity but lacks sensitivity.
• Existing optical tools face limitations in combining sensitivity and specificity.

Purpose of the Study:

• To develop a hybrid technique integrating the sensitivity of fluorescence and the specificity of Raman spectroscopy.
• To overcome the limitations of current optical detection methods for molecular analysis.
• To enable advanced imaging and spectroscopy with enhanced chemical information.

Main Methods:

• Developed Stimulated Raman Excited Fluorescence (SREF) by combining stimulated Raman pumping with fluorescence upconversion.
• Encoded vibrational information into the fluorescence excitation spectrum.
• Utilized narrow vibrational linewidth for multiplexed imaging and single-molecule detection.

Main Results:

• Demonstrated multiplexed SREF imaging in cells, overcoming the "color barrier" of fluorescence.
• Achieved all-far-field single-molecule Raman spectroscopy and imaging without plasmonic enhancement.
• Successfully integrated high sensitivity and fine chemical specificity in a single technique.

Conclusions:

• SREF merges the strengths of Raman and fluorescence spectroscopy.
• This hybrid technique offers a valuable new tool for chemistry and biology.
• SREF enables unprecedented molecular analysis capabilities.