SPECTRAL PROPERTIES OF A BENZOTHIAZOLE DYE MODIFIED WITH POLYETHYLENE GLYCOL

2021 ◽  
Vol 88 (6) ◽  
pp. 852-857
Author(s):  
A. A. Maskevich
Keyword(s):  
Absorption Spectrum ◽  
Polyethylene Glycol ◽  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Plasma Proteins ◽  
Spectral Properties ◽  
Amyloid Fibrils ◽  
Strong Dependence ◽  
Molecular Rotor ◽  
Blood Plasma Proteins

The spectral properties of a new benzothiazole dye modified with polyethylene glycol have been investigated. A strong dependence of the fluorescence quantum yield on the viscosity and polarity of the medium has been shown, i.e. the conjugation of the dye with polyethylene glycol does not lead to the loss of the properties of the molecular rotor, while significantly reduces its aggregation. When incorporated into amyloid fibrils, the quantum yield of the dye increases by more than 40 times; the new dye can be regarded as an efficient fluorescent probe for amyloid fibrils detection and research. In this case, not only the intensity, but also the position of the absorption spectrum can be used as a sensitive parameter. The presence of blood plasma proteins (albumins) in the solution has practically no effect on the position of the absorption spectrum and has little effect on the fluorescence intensity of the probe.

scholarly journals Spectral properties and factors determining high quantum yield of thioflavin T incorporated in amyloid fibrils

2010 ◽  
Vol 24 (1-2) ◽  
pp. 169-172 ◽  
Author(s):  
A. I. Sulatskaya ◽  
K. K. Turoverov ◽  
I. M. Kuznetsova
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Spectral Properties ◽  
Molecular Mechanisms ◽  
Amyloid Fibrils ◽  
Thioflavin T ◽  
Monomeric Form ◽  
High Quantum Yield ◽  
High Quantum ◽  
Common Opinion

Benzthiazole dye thioflavin T (ThT) is widely used for studying amyloid fibrils structure and formation. Nevertheless, till now there is no common opinion concerning molecular mechanisms of ThT binding to amyloid fibrils and the reasons of dramatic increase of its fluorescence quantum yield on incorporation into amyloid fibrils. Our data prove that ThT molecules incorporate in amyloid fibrils in monomeric form and there is no ground to suppose the formation of ThT dimers, eximers, or micelles. It was shown that the increase of quantum yield of ThT incorporated in amyloid fibrils is caused by restriction of benzthiazole and aminobenzene rings torsion fluctuations about each other.

Investigation of a novel triazatetrabenzcorrole photosensitizer

2002 ◽  
Vol 06 (07) ◽  
pp. 484-488 ◽  
Author(s):  
Zhenglin Song ◽  
Fushi Zhang ◽  
Xue Li ◽  
Shek-Kiu Chan ◽  
Fuqun Zhao ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Photodynamic Therapy ◽  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Fluorescence Emission Spectra ◽  
Oxygen Generation ◽  
Singlet Oxygen Generation ◽  
Sulfo Groups

A novel phthalocyanine-like photosensitizer, oxophosphorus(V) tetrasulfotriaza-tetrabenzcorrole ( POTBCS 4), has been synthesized. Its structure and absorption spectrum are unique. POTBCS 4 has an axial P = O group and peripheral sulfo groups. The fluorescence emission spectra, fluorescence quantum yield and quantum yield of singlet oxygen generation have been studied. The uptake and the photodynamic activities against HeLa cells were measured. The results indicated that POTBCS 4 was a potential photosensitizer for photodynamic therapy (PDT).

Interaction of Thioflavin T with Amyloid Fibrils: Fluorescence Quantum Yield of Bound Dye

2012 ◽  
Vol 116 (8) ◽  
pp. 2538-2544 ◽  
Author(s):  
Anna I. Sulatskaya ◽  
Irina M. Kuznetsova ◽  
Konstantin K. Turoverov
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Amyloid Fibrils ◽  
Thioflavin T

Electronic Structure and Photophysical Characteristics of Substituted 3-(2-Benzthiazolyl)-Coumarins and Coumarinimines

1987 ◽  
Vol 42 (9) ◽  
pp. 987-993
Author(s):  
P. Nikolova ◽  
N. Tyutyulkova ◽  
V. Dryanska
Keyword(s):  
Electronic Structure ◽  
Quantum Yield ◽  
Quantum Chemical ◽  
Fluorescence Quantum Yield ◽  
Spectral Properties ◽  
High Fluorescence ◽  
High Fluorescence Quantum Yield

The spectral properties of a group of 3-(2-benzthiazolyl)-coumarins and coumarinimines, some of them having high fluorescence quantum yield (Qf > 0.7), are described.The quantum -chemical investigations show that the main chromophore of this group of dyes is the 3 -(2-thiazolyl)-2 H -pyran -2-one fragmenti.e . the coumarin (coumarinimine) and the benzthiazolyl fragments are not separate chromophores.

Synthesis, Structure and Spectral Properties of Pyrylium Salts and Their Derivatives. I. 5,6-Dihydro-benzo(c)xanthylium Salts

1987 ◽  
Vol 42 (1) ◽  
pp. 43-48 ◽  
Author(s):  
T. G. Deligeorgiev ◽  
P. Nikolov ◽  
N. Tyutyulkov
Keyword(s):  
Quantum Yield ◽  
Organic Solvents ◽  
Fluorescence Quantum Yield ◽  
Spectral Properties ◽  
Absorption Maximum ◽  
Molar Absorptivity ◽  
Pyrylium Salts ◽  
Quantumchemical Calculations ◽  
Wavelength Absorption

The synthesis and spectral properties of a group of xanthylium salts are described. The longest wavelength absorption maximum in organic solvents (ethanol, 1,4-dioxane, acetonitrile) is the region 17 000-20 000 cm-1, the molar absorptivity exceeding 30 000 1 • mol-1 cm-1. The fluorescence Frank Condon transition is in the region 16 000-19 000 cm-1, the fluorescence quantum yield of some of the compounds is greater than 0.9. The relation between the structure and the spectral properties of the molecules is interpreted by means of PPP-quantumchemical calculations.

scholarly journals 7-Amino-actinomycin D as a cytochemical probe. I. Spectral properties.

1975 ◽  
Vol 23 (11) ◽  
pp. 793-799 ◽  
Author(s):  
J E Gill ◽  
M M Jotz ◽  
S G Young ◽  
E J Modest ◽  
S K Sengupta
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Spectral Properties ◽  
Absorption Maximum ◽  
Actinomycin D ◽  
Spectral Characteristics ◽  
Fluorescence Emission ◽  
Fluorescence Excitation ◽  
Fluorescence Characteristics ◽  
Ethanesulfonic Acid

The optical absorption and fluorescence characteristics of 7-animo-actinomycin D were determined to evaluate its potential as a fluorescent cytochemical probe. At pH 7.0, the absorption maximum and fluorescence excitation maximum are both at 503 nm; the fluorescence emission is at 675 nm. When this compound forms complexes with DNA in solution, the absorption and fluorescence excitation maxima shift to 543 nm and the fluorescence emission shifts to 655 nm. The fluorescence quantum yield is 0.016 for 7-amino-actinomycin D free in solution and 0.01-0.02 for complexes with native DNA. The 7-amino-actinomycin D also exhibits fluorescence shifts characteristic of binding when put into solution with poly(dG-dC) poly(dG-dC), but not with poly(dI-dC) poly(dI-dC). The spectral characteristics are the same at pH 7.0 whether the solvent is 0.01 M PO4 with 0.0001 M EDTA or Earle's salts with 0.025 M N-2-hydroxyethylpiperazine-N1-2-ethanesulfonic acid.

scholarly journals Fluorescence Quantum Yield of Thioflavin T in Rigid Isotropic Solution and Incorporated into the Amyloid Fibrils

PLoS ONE ◽  
2010 ◽  
Vol 5 (10) ◽  
pp. e15385 ◽  
Author(s):  
Anna I. Sulatskaya ◽  
Alexander A. Maskevich ◽  
Irina M. Kuznetsova ◽  
Vladimir N. Uversky ◽  
Konstantin K. Turoverov
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Amyloid Fibrils ◽  
Thioflavin T ◽  
Isotropic Solution

scholarly journals Binding Modes of a Phenylpyridinium Styryl Fluorescent Dye with Cucurbiturils

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5111
Author(s):  
Adrien Paudics ◽  
Dóra Hessz ◽  
Márton Bojtár ◽  
Benjámin Gyarmati ◽  
András Szilágyi ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Polyethylene Glycol ◽  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Phenyl Ring ◽  
Intramolecular Charge Transfer ◽  
Theoretical Calculations ◽  
Binding Modes ◽  
Pyridinium Ring ◽  
Solvatochromic Dye

In order to explore how cucurbituril hosts accommodate an N-phenyl-pyridinium derivative guest, the complexation of the solvatochromic dye, 4-(4-(dimethylamino)styryl)-1-phenylpyridinium iodide (PhSt) with α,α′,δ,δ′-tetramethyl-cucurbit[6]uril (Me4CB6) and cucurbit[7]uril (CB7) was investigated by absorption spectroscopic, fluorescence and NMR experiments. In aqueous solutions, PhSt forms 1:1 complexes with both cucurbiturils, the complex with CB7 has a higher stability constant (Ka = 6.0 × 106 M−1) than the complex with Me4CB6 (Ka = 1.1 × 106 M−1). As revealed by NMR experiments and confirmed by theoretical calculations, CB7 encapsulates the whole phenylpyridinium entity of the PhSt cation guest, whereas the cavity of Me4CB6 includes only the phenyl ring, the pyridinium ring is bound to the carbonyl rim of the host. The binding of PhSt to cucurbiturils is accompanied by a strong enhancement of the fluorescence quantum yield due to the blocking of the deactivation through a twisted intramolecular charge transfer (TICT) state. The TICT mechanism in PhSt was characterized by fluorescence experiments in polyethylene glycol (PEG) solvents of different viscosities. The PhSt-CB7 system was tested as a fluorescence indicator displacement (FID) assay, and it recognized trimethyl-lysine selectively over other lysine derivatives.

scholarly journals Fluorescent properties anionic derivative of thioflavin T

2021 ◽  
pp. 4-14
Author(s):  
Alexander A. Maskevich
Keyword(s):  
Quantum Yield ◽  
Strong Dependence ◽  
Minimum Energy ◽  
Experimental Studies ◽  
Fluorescence Decay ◽  
Thioflavin T ◽  
Main Process ◽  
Molecular Rotor ◽  
Fluorescent Properties ◽  
Twisted State

We have investigated the spectral properties of a new benzothiazole dye – a thioflavin T derivative – 3-sulfopropyl-5-methoxy-2-[3-(3,5-diethyl-2-benzothiazolidene)-1-propienyl]-benzothiazolium (Th-C11). Based on quantum-chemical calculations, it is shown that the molecule in the ground state has a flat structure. In an excited state, the minimum energy corresponds to a twisted conformation, in which the aromatic fragments are arranged orthogonally. Since the twisted state is non-fluorescent, the transition to this state (torsion relaxation) is a quenching process. Th-C11 dye exhibits the properties of a fluorescent molecular rotor. As a result of experimental studies, it was found that torsion relaxation of molecular fragments is the main process that determines the strong dependence of the quantum yield and the duration of fluorescence decay on the viscosity of the solvent. A characteristic feature of this dye is the sensitivity of the fluorescence parameters – the quantum yield, the decay duration and the position of the spectrum not only to the viscosity, but also to the polarity of the medium. The paper also explains the dependence of the position of the absorption and fluorescence spectra on the polarity and viscosity of the solvent as a result of the manifestation of the processes of torsion and solvation relaxation of the chromophore and solvent molecules.

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