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Exploration of the Thioflavin T in complex systems for peptide drug delivery – Mechanistic Mapping of Thioflavin T Matrix Effects

Coker, Ewura Abena LU (2026) KEMR20 20261
Department of Chemistry
Computational Chemistry
Abstract
Thioflavin T (ThT) is widely used as a fluorescent probe for amyloid fibrils, yet its fluorescence can also be enhanced in non-fibrillar systems. Here, the photophysical behaviour of ThT was investigated in sodium dodecyl sulfate (SDS), sucrose laurate (SL), sodium caprate (C10), and lanreotide-containing assemblies across acetate (pH 4.0), phosphate (pH 7.4), and Gly-Gly (pH 8.5) buffers using UV–visible absorption spectroscopy, steady-state fluorescence spectroscopy, time-correlated single-photon counting (TCSPC), and dynamic light scattering.
SDS and C10 produced concentration-dependent red shifts in the ThT absorption spectra of ~412 to 429 nm, while SL generated a red shift in the ThT absorption spectra of ~412 to 426 nm which was... (More)
Thioflavin T (ThT) is widely used as a fluorescent probe for amyloid fibrils, yet its fluorescence can also be enhanced in non-fibrillar systems. Here, the photophysical behaviour of ThT was investigated in sodium dodecyl sulfate (SDS), sucrose laurate (SL), sodium caprate (C10), and lanreotide-containing assemblies across acetate (pH 4.0), phosphate (pH 7.4), and Gly-Gly (pH 8.5) buffers using UV–visible absorption spectroscopy, steady-state fluorescence spectroscopy, time-correlated single-photon counting (TCSPC), and dynamic light scattering.
SDS and C10 produced concentration-dependent red shifts in the ThT absorption spectra of ~412 to 429 nm, while SL generated a red shift in the ThT absorption spectra of ~412 to 426 nm which was not expected and the strongest fluorescence enhancement. Lanreotide-containing systems displayed a distinct excitation shift from approximately 424 to 440 nm and enhanced fluorescence intensity. Despite these pronounced steady-state spectral changes, SDS, C10 and SL systems exhibited short fluorescence lifetimes (0.05–0.26 ns), indicating microenvironmental confinement rather than rigid amyloid-like immobilization. These findings demonstrate that ThT responds to a combination of electrostatic interactions, hydrophobic partitioning, and supramolecular organization, highlighting the importance of combining steady-state and time-resolved fluorescence measurements when interpreting ThT responses in complex molecular environments. (Less)
Popular Abstract
When a Common Amyloid Dye Sends Mixed Signals: Understanding the Behaviour of Thioflavin T in Complex Molecular Environments

Thioflavin T (ThT) is a fluorescent dye widely used by scientists to detect amyloid fibrils; protein structures associated with diseases such as Alzheimer's and Parkinson's disease. When ThT binds to these highly ordered structures, its fluorescence increases dramatically, making it a useful tool for monitoring protein aggregation. However, recent studies have shown that ThT can also become highly fluorescent in systems that do not contain amyloid fibrils. This raises an important question: does a strong ThT signal always indicate the presence of amyloid structures?
The aim of this study was to investigate how... (More)
When a Common Amyloid Dye Sends Mixed Signals: Understanding the Behaviour of Thioflavin T in Complex Molecular Environments

Thioflavin T (ThT) is a fluorescent dye widely used by scientists to detect amyloid fibrils; protein structures associated with diseases such as Alzheimer's and Parkinson's disease. When ThT binds to these highly ordered structures, its fluorescence increases dramatically, making it a useful tool for monitoring protein aggregation. However, recent studies have shown that ThT can also become highly fluorescent in systems that do not contain amyloid fibrils. This raises an important question: does a strong ThT signal always indicate the presence of amyloid structures?
The aim of this study was to investigate how different molecular environments influence the behaviour of ThT. In particular, we examined whether fluorescence enhancement results from true amyloid-like binding or simply from confinement of the dye within organized molecular assemblies. To answer this question, ThT was studied in three different surfactant systems, sodium dodecyl sulfate (SDS), sucrose laurate (SL), and sodium caprate (C10), as well as in a self-assembling peptide system based on lanreotide. Experiments were performed in acidic, neutral, and basic buffer solutions to determine how pH and solution composition affect the response of the dye.
Several spectroscopic techniques were used to monitor changes in ThT behaviour. Ultraviolet-visible absorption spectroscopy and fluorescence spectroscopy were used to examine changes in colour and fluorescence intensity, while time-resolved fluorescence measurements provided information about how long the dye remained in its excited state after absorbing light. Dynamic light scattering was also used to investigate the formation of molecular assemblies in solution.
The results showed that the fluorescence response of ThT depended strongly on both the surfactant system and the buffer environment. Surprisingly, the largest fluorescence enhancement was observed for the non-ionic surfactant sucrose laurate rather than the negatively charged SDS system. Significant fluorescence increases were also observed for C10 and lanreotide-containing samples. However, time-resolved measurements revealed that the fluorescence lifetimes remained very short, indicating that the dye was not bound within rigid amyloid-like structures. Instead, the results suggest that organized molecular environments can restrict the motion of ThT sufficiently to increase fluorescence without requiring the presence of amyloid fibrils. (Less)
Please use this url to cite or link to this publication:
author
Coker, Ewura Abena LU
supervisor
organization
course
KEMR20 20261
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Amyloid, Biochemistry, Fluorescence enhancement, Lanreotide, Pharmaceutical Chemistry, Surfactants, Thioflavin T
language
English
id
9236343
date added to LUP
2026-06-16 13:37:02
date last changed
2026-06-16 13:37:02
@misc{9236343,
  abstract     = {{Thioflavin T (ThT) is widely used as a fluorescent probe for amyloid fibrils, yet its fluorescence can also be enhanced in non-fibrillar systems. Here, the photophysical behaviour of ThT was investigated in sodium dodecyl sulfate (SDS), sucrose laurate (SL), sodium caprate (C10), and lanreotide-containing assemblies across acetate (pH 4.0), phosphate (pH 7.4), and Gly-Gly (pH 8.5) buffers using UV–visible absorption spectroscopy, steady-state fluorescence spectroscopy, time-correlated single-photon counting (TCSPC), and dynamic light scattering.
SDS and C10 produced concentration-dependent red shifts in the ThT absorption spectra of ~412 to 429 nm, while SL generated a red shift in the ThT absorption spectra of ~412 to 426 nm which was not expected and the strongest fluorescence enhancement. Lanreotide-containing systems displayed a distinct excitation shift from approximately 424 to 440 nm and enhanced fluorescence intensity. Despite these pronounced steady-state spectral changes, SDS, C10 and SL systems exhibited short fluorescence lifetimes (0.05–0.26 ns), indicating microenvironmental confinement rather than rigid amyloid-like immobilization. These findings demonstrate that ThT responds to a combination of electrostatic interactions, hydrophobic partitioning, and supramolecular organization, highlighting the importance of combining steady-state and time-resolved fluorescence measurements when interpreting ThT responses in complex molecular environments.}},
  author       = {{Coker, Ewura Abena}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Exploration of the Thioflavin T in complex systems for peptide drug delivery – Mechanistic Mapping of Thioflavin T Matrix Effects}},
  year         = {{2026}},
}