Electronic Preresonance Stimulated Raman Scattering Spectromicroscopy Using Multiple-Plate Continuum.
J Phys Chem B
; 127(31): 6896-6902, 2023 Aug 10.
Article
in En
| MEDLINE
| ID: mdl-37494414
ABSTRACT
Stimulated Raman scattering (SRS) spectromicroscopy is a powerful technique that enables label-free detection of chemical bonds with high specificity. However, the low Raman cross section due to typical far-electronic resonance excitation seriously restricts the sensitivity and undermines its application to bio-imaging. To address this bottleneck, the electronic preresonance (EPR) SRS technique has been developed to enhance the Raman signals by shifting the excitation frequency toward the molecular absorption. A fundamental weakness of the previous demonstration is the lack of dual-wavelength tunability, making EPR-SRS only applicable to a limited number of species in the proof-of-concept experiment. Here, we demonstrate the EPR-SRS spectromicroscopy using a multiple-plate continuum (MPC) light source able to examine a single vibration mode with independently adjustable pump and Stokes wavelengths. In our experiments, the CâC vibration mode of Alexa 635 is interrogated by continuously scanning the pump-to-absorption frequency detuning throughout the entire EPR region enabled by MPC. The results exhibit 150-fold SRS signal enhancement and good agreement with the Albrecht A-term preresonance model. Signal enhancement is also observed in EPR-SRS images of the whole Drosophila brain stained with Alexa 635. With the improved sensitivity and potential to implement hyperspectral measurement, we envision that MPC-EPR-SRS spectromicroscopy can bring the Raman techniques closer to a routine in bio-imaging.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
J Phys Chem B
Journal subject:
QUIMICA
Year:
2023
Document type:
Article
Affiliation country:
Taiwan