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Updated: Dec 20, 2025
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Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional π-conjugate Systems
Published on: February 10, 2020
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Fluorescence-enhanced second harmonic normal Raman scattering in β-carotene
Mengying Zheng1, Jingkai Bi1, Yixin Chen1
1College of Physics, Jilin University, Changchun 130012, China.
Summary
High pressure Raman spectroscopy reveals two phase transitions in beta-carotene (a vital biomolecule). New fluorescence enhancement mechanisms were also proposed for Raman spectroscopy.
Area of Science:
- Biochemistry
- Spectroscopy
- Materials Science
Background:
- Beta-carotene is a vital biomolecule in the carotenoid family.
- Understanding its photophysical properties is crucial for biosystem applications.
- Electronic and vibrational spectra provide insights into these properties.
Purpose of the Study:
- To investigate the high-pressure behavior of beta-carotene using Raman spectroscopy.
- To identify potential phase transitions under extreme pressure conditions.
- To explore mechanisms influencing Raman band intensities.
Main Methods:
- In-situ high-pressure Raman spectroscopy up to 26 GPa.
- High-pressure UV-Vis absorption measurements.
- Analysis of frequency-pressure relationships and Raman band intensities.
Main Results:
- Two phase transitions were identified at approximately 7 GPa and 14 GPa.
- Resonance Raman enhancement and a novel fluorescence enhancement mechanism were observed.
- Intensity changes in Raman bands were correlated with pressure-induced effects.
Conclusions:
- High pressure significantly alters the structural and photophysical properties of beta-carotene.
- The study proposes a new fluorescence enhancement mechanism for Raman spectroscopy.
- These findings offer new approaches for analyzing biomolecules under pressure.
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