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Electroabsorption and Stark Fluorescence Spectroscopies of Thioflavin T
Ahatashamul Islam1, Yudai Kikuchi1, Toshifumi Iimori1
1Department of Sciences and Informatics, Muroran Institute of Technology, Mizumoto-cho 27-1, Muroran, Hokkaido050-8585, Japan.
The Journal of Physical Chemistry. A
|February 6, 2023
Summary
Thioflavin T (ThT) fluorescence is quenched by electric fields on amyloid fibrils. This study quantifies these fields using electroabsorption and Stark fluorescence, revealing insights into amyloid fibril surface properties.
Area of Science:
- Biophysics
- Chemical Physics
- Materials Science
Background:
- Thioflavin T (ThT) is a fluorescent dye widely used to detect amyloid fibril formation.
- Amyloid fibrils are associated with neurodegenerative diseases.
- Strong electrostatic fields are crucial for biological functions and chemical reactions.
Purpose of the Study:
- To investigate the impact of external electric fields on the photophysics of Thioflavin T.
- To quantify the electric field strength at the surface of amyloid fibrils.
Main Methods:
- Electroabsorption spectroscopy
- Stark fluorescence spectroscopy
- Analysis of ThT fluorescence quenching
Main Results:
- ThT absorption spectrum exhibits locally excited (LE) and charge transfer (CT) states.
- External electric fields enhance coupling between LE and CT states in ThT.
- This enhanced coupling leads to significant fluorescence quenching of ThT.
Conclusions:
- The fluorescence quenching efficiency of ThT is directly related to the electric field strength on amyloid fibril surfaces.
- This study provides a method to infer and quantify the electric field strength of amyloid fibril surfaces.
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