Multiplex Chemical Imaging Based on Broadband Stimulated Raman Scattering Microscopy

Area of Science:

• Nonlinear optical microscopy
• Vibrational spectroscopy
• Chemical imaging

Background:

• Stimulated Raman scattering (SRS) microscopy offers label-free chemical imaging of molecular vibrations.
• Standard SRS microscopy is limited to single-frequency imaging, restricting chemical specificity and information retrieval.
• Hyperspectral data acquisition is crucial for enhanced chemical analysis.

Purpose of the Study:

• To present a protocol for chemical imaging using broadband SRS microscopy.
• To demonstrate the capability of broadband SRS for detailed chemical analysis.
• To enable quantitative determination of chemical constituents in a sample.

Main Methods:

• Development of a home-built broadband SRS microscope.
• Utilizing a custom differential multichannel-lock-in amplifier for detection.
• Implementing chemometric analysis on acquired hyperspectral data.

Main Results:

• Acquisition of vibrational Raman spectra at a per-pixel level.
• Successful identification of distinct chemical species within a mixture.
• Quantitative determination of the relative concentrations of identified chemical species.

Conclusions:

• Broadband SRS microscopy significantly enhances chemical specificity and information content compared to narrowband SRS.
• The presented protocol facilitates comprehensive chemical analysis and quantitative measurements.
• This technique holds potential for advanced material science and biological imaging applications.