Electronically Preresonant Stimulated Raman Scattering Microscopy of Weakly Fluorescing Chromophores

Area of Science:

• Biophotonics
• Chemical Imaging
• Microscopy

Background:

• Stimulated Raman Scattering (SRS) microscopy offers advanced chemical imaging capabilities.
• Current SRS microscopy applications are limited by relatively low sensitivity.
• Exploiting electronic preresonances has previously boosted spontaneous Raman microscopy sensitivity.

Purpose of the Study:

• To investigate the effectiveness of electronic preresonances in enhancing SRS microscopy sensitivity.
• To demonstrate the application of this technique with low quantum yield chromophores.
• To explore the photophysics and background signals under preresonant conditions.

Main Methods:

• Utilized organic fluorophores and low quantum yield chromophores.
• Applied electronic preresonance excitation principles to SRS microscopy.
• Investigated photophysical properties and background noise.
• Performed imaging experiments on fixed and live cells.

Main Results:

• Demonstrated significant sensitivity enhancement in SRS microscopy using electronic preresonances.
• Successfully applied the technique with low quantum yield chromophores.
• Characterized photophysics and identified sources of background noise.
• Achieved high-quality imaging of weakly fluorescing labels.

Conclusions:

• Electronic preresonance excitation is a viable strategy to significantly improve SRS microscopy sensitivity.
• This approach broadens the applicability of SRS microscopy for imaging challenging biological samples.
• The findings pave the way for more sensitive and versatile chemical imaging in biological research.