Label-free vibrational microscopy to overcome limitations in space, penetration depth, and sensitivity

Abstract: 

For many years, scientists have utilized molecular vibrational motions in spectroscopy and microscopy to observe target specimens conveniently. This observation allows for measuring the interaction between light and matter, as shown by phenomena like Raman scattering and infrared absorption. However, practical Raman scattering measurements have been challenging due to its low signal intensity. While the signal strength in infrared absorption is relatively higher than Raman scattering, the diffraction limit has limited progress in imaging techniques. Furthermore, both methods have faced significant restrictions when measuring samples with complex scattering and variations, such as skin.

Developing vibrational microscopy is crucial for future optical investigations of biomolecules and material structures. As a member of the vibrational microscopy team at the IBS Center for Molecular Spectroscopy and Dynamics (CMSD), I continuously strive to develop novel techniques to address these issues. Our team has developed super-resolution mid-infrared photothermal microscopy and sensitive stimulated Raman scattering microscopy close to the shot-noise limit. We could describe tiny biomolecular vesicles and polymer beads with visible spatial resolution and reached unprecedented noise levels. Additionally, we investigated the unprecedented penetration depth of coherent Raman scattering microscopy using the wavefront correction technique.

References:

[1] J. Phys. Chem. Lett. 2019. 10, 2857.

[2] J. Phys. Chem. B 2020. 124, 2591.

[3] bioRxiv https://doi.org/10.1101/2022.09.14.507912

20240321_대학원세미나_임종민 교수.pdf