Electronic Preresonance Stimulated Raman Scattering Spectromicroscopy Using Multiple-Plate Continuum
Journal
Journal of Physical Chemistry B
Journal Volume
127
Journal Issue
31
Start Page
6896
End Page
6902
ISSN
15206106
Date Issued
2023
Author(s)
Huang, Guan-Jie
Li, Cheng-Wei
Lee, Po-Yi
Su, Jia-Xuan
Chao, Kuo-Chuan
Chiang, Ann-Shyn
Cheng, Ji-Xin
Chen, Bo-Han
Lu, Chih-Hsuan
Chu, Shi-Wei
Yang, Shang-Da
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 C?�C 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. © 2023 American Chemical Society.
Publisher
American Chemical Society
Type
journal article