A study of the light quenching of the fluorescence of phthalimide solutions

Rudik, K. I.; Pikulik, L. G.; Senkevich, L. P.; Kostko, M. Ya.; Maksimov, A. I.

doi:10.1007/bf00618027

Cited by 3 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Consider now that the sample is illuminated with a timedelayed long-wavelength pulse which overlaps with the emission of the relaxed state (Scheme 2) and that the lifetime τ is comparable to the relaxation time τ R . The relative amounts of fluorescence quenching are known to be proportional to the amplitudes of the emission spectrum at the quenching wavelength, [23][24][25][26] as expected from the prediction of Einstein for stimulated emission. 26 Hence, one expects preferential quenching of the solvent-relaxed emission and a blue shift in the steady-state emission spectrum due to the increased relative contribution of the unrelaxed state (Scheme 2, bottom).…”

Section: Overview Of Fq By Se and Spectral Relaxationmentioning

confidence: 99%

Effect of Fluorescence Quenching by Stimulated Emission on the Spectral Properties of a Solvent-Sensitive Fluorophore

et al. 1996

View full text Add to dashboard Cite

We examined the emission spectra and wavelength-dependent anisotropies of the solvent-sensitive fluorophore 4-(dimethylamino)-4′-cyanostilbene (DCS) under condition of fluorescence quenching by stimulated emission. The sample was illuminated with a train of 10 ps pulses at 285 nm, and a train of stimulating pulses at 570 nm which were delayed by a time t d relative to the excitation. Stimulated emission of DCS was demonstrated to occur by observation of gain in the long-wavelength beam. Illumination on the long-wavelength side of the emission spectrum with the long-wavelength time-delayed pulses resulted in a blue shift of the emission spectrum, and a progressive decrease of the emission anisotropy as the observation wavelength increased toward the stimulating wavelength. The spectral shifts and wavelength-dependent anisotropies of DCS were more pronounced in more viscous solvents where spectral relaxation is incomplete during the excited state lifetime. Light quenching of DCS in a low-viscosity solvent revealed no spectral shifts or wavelengthdependent anisotropies. Control measurements using acridine orange, which is relatively insensitive to solvent polarity, did not show any spectral shift or wavelength-dependent anisotropy with light quenching. The data for DCS can be explained by the presence of a time-dependent spectral shift and wavelength-selective quenching of the longer wavelength emission. In this model the relaxed state is formed following excitation of the unrelaxed state, and the relaxed state is preferentially quenched by long-wavelength illumination. Comparison of the data with model calculations indicates the presence of at least two spectral relaxation times. These results demonstrate that light quenching by stimulated emission acts selectively based on overlap of the stimulating wavelength with the emission spectrum. Observation of the emission spectrum in the presence of time-delayed and power-controlled long-wavelength pulses can be used to study time-dependent excited state processes.

show abstract

Section: Overview Of Fq By Se and Spectral Relaxationmentioning

confidence: 99%

Effect of Fluorescence Quenching by Stimulated Emission on the Spectral Properties of a Solvent-Sensitive Fluorophore

et al. 1996

View full text Add to dashboard Cite

show abstract

“…One final piece of evidence for spectral relaxation in proteins is from the red edge effects. For polar fluorophores in polar viscous solvents the emission spectra shift to longer wavelengths with longer wavelength excitation (112)(113)(114)(115)(116)(117)(118)(119)(120)(121)(122). This effect is due to excitation of fluorophores that are interacting most strongly with the solvent when using excitation on the red side of the absorption.…”

Section: Red-edge Effectsmentioning

confidence: 99%

On Spectral Relaxation in Proteins†¶‖

Lakowicz

2007

Photochemistry and Photobiology

View full text Add to dashboard Cite

During the past several years there has been debate about the origins of nonexponential intensity decays of intrinsic tryptophan (trp) fluorescence of proteins, especially for single tryptophan proteins (STP). In this review we summarize the data from diverse sources suggesting that time‐dependent spectral relaxation is a ubiquitous feature of protein fluorescence. For most proteins, the observations from numerous laboratories have shown that for trp residues in proteins (1) the mean decay times increase with increasing observation wavelength; (2) decay associated spectra generally show longer decay times for the longer wavelength components; and (3) collisional quenching of proteins usually results in emission spectral shifts to shorter wavelengths. Additional evidence for spectral relaxation comes from the time‐resolved emission spectra that usually shows time‐dependent shifts to longer wavelengths. These overall observations are consistent with spectral relaxation in proteins occurring on a subnanosecond timescale. These results suggest that spectral relaxation is a significant if not dominant source of nonexponential decay in STP, and should be considered in any interpretation of nonexponential decay of intrinsic protein fluorescence.

show abstract

“…1.7. Influência do meio nos espectros eletrônicos As interações intermoleculares determinam as propriedades ópticas de um sistema e, portanto, deve-se considerar fatores como a estrutura e a conformação moleculares, além da natureza das interações que ocorrem entre a molécula fluorescente em estudo e o meio no qual está inserida [29,31,35,[41][42][43][44][45][49][50][51][52][53] . Neste item serão apresentados alguns aspectos dos possíveis efeitos do meio sobre os espectros de fluorescência.…”

Section: O Pericondensado: Pirenounclassified

“…Várias são as formas com que a resposta óptica de uma molécula pode ser perturbada pelo meio. Moléculas como pireno e outros hidrocarbonetos aromáticos policíclicos não exibem deslocamento espectral, como ocorre para outras moléculas chamadas solvatocrômicas, mas exibem uma variação na intensidade relativa das bandas vibracionais que compõem seus espectros eletrônicos de emissão, dependendo da polaridade do meio em que se encontram [29,[49][50][51][52][53] . Portanto, além de deslocamentos espectrais, a estrutura vibracional dos espectros de fluorescência e de absorção pode ser influenciada pelas interações com o meio, desde que haja uma mudança no envelope de Franck-Condon devida a modificações das superfícies de potenciais moleculares causadas pela solvatação destas moléculas [48][49][50][51][52][53][54][55][56][57][58][59][60][61][62] .…”

Section: Deslocamento Espectral Por Interações Com O Solventeunclassified

“…Aqui, então, o espectro de fluorescência depende significativamente do comprimento de onda usado para a excitação do sistema. A manifestação mais evidente dessa dependência é o chamado red-edge effect (REE) que ocorre quando se procede a excitação em um limite do espectro de absorção de menor energia, produzindo um espectro deslocado para comprimentos de onda maiores que quando o processo de excitação emprega comprimentos de onda de maiores energias [46,[48][49][50][51][52][53][54][55][56][57] .…”

Section: Alargamento Espectralunclassified

See 1 more Smart Citation

Fotofisica de hidrocarbonetos aromaticos condensados em matrizes polimericas vinilicas

Martins¹,

Atvars²

View full text Add to dashboard Cite

show abstract

A study of the light quenching of the fluorescence of phthalimide solutions

Cited by 3 publications

References 0 publications

Effect of Fluorescence Quenching by Stimulated Emission on the Spectral Properties of a Solvent-Sensitive Fluorophore

Effect of Fluorescence Quenching by Stimulated Emission on the Spectral Properties of a Solvent-Sensitive Fluorophore

On Spectral Relaxation in Proteins†¶‖

Fotofisica de hidrocarbonetos aromaticos condensados em matrizes polimericas vinilicas

Contact Info

Product

Resources

About