Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1573-4994
    Keywords: Fluorescence anisotropy decays ; frequency-domain fluorescence spectroscopy ; review
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract This didactic paper summarizes the mathematical expressions needed for analysis of fluorescence anisotropy decays from polarized frequency-domain fluorescence data. The observed values are the phase angle difference between the polarized components of the emission and the modulated anisotropy, which is the ratio of the polarized and amplitude-modulated components of the emission. This procedure requires a separate measurement of the intensity decay of the total emission. The expressions are suitable for any number of exponential components in both the intensity decay and the anisotropy decay. The formalism is generalized for global analysis of anisotropy decays measured at different excitation wavelengths and for different intensity decay times as the result of quenching. Additionally, we describe the expressions required for associated anisotropy decays, that is, anisotropy decays where each correlation time is associated with a decay time present in the anisotropy decay. And finally, we present expressions appropriate for distributions of correlation times. This article should serve as a reference for researchers using frequency-domain fluorometry.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1573-4994
    Keywords: Time-resolved fluorescence spectroscopy ; two photon-induced fluorescence ; light quenching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Time-resolved fluorescence spectroscopy is presently regarded as a research tool in biochemistry, biophysics, and chemical physics. Advances in laser technology, the development of long-wavelength probes, and the use of lifetime-based methods, are resulting in the rapid migration of timeresolved fluorescence to the clinical chemistry lab, the patient's bedside, and even to the doctor's office and home health care. Additionally, time-resolved imaging is now a reality in fluorescence microscopy and will provide chemical imaging of a variety of intracellular analytes and/or cellular phenomena. Future horizons of state-of-the-art spectroscopy are also described. Two photon-induced fluorescence provides an increased information content to time-resolved data. Two photoninduced fluorescence, combined with fluorescence microscopy and time-resolved imaging, promises to provide detailed three-dimensional chemical imaging of cells. Additionally, it has recently been demonstrated that the pulses from modern picosecond lasers can be used to quench and/or modify the excited-state population by stimulated emission since the stimulated photons are directed along the quenching beam and are not observed. The phenomenon of light quenching should allow a new class of multipulse time-resolved fluorescence experiments, in which the excited-state population is modified by additional pulses to provide highly oriented systems.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1573-4994
    Keywords: Anisotropy ; 4-dimethylamino-4′-cyanostilbene ; light quenching ; time-resolved fluorescence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We examined the emission wavelength-dependent anisotropies of the solvent-sensitive fluorophore 4-dimethylamino-4′-cyanostilbene (DCS) under conditions of light quenching by polarized time-delayed quenching pulses. Illumination on the long-wavelength side of the emission spectrum with time-delayed light pulses resulted in a progressive decrease in the emission anisotropy as the observation wavelength increased toward the stimulating wavelength. The anisotropy changes of DCS were most wavelength dependent when spectral relaxation occurred during the excited-state lifetime. Light quenching of DCS in a low-viscosity solvent revealed no wavelength-dependent anisotropies. Control measurements using a solvent-insensitive fluorophore did not show any wavelength-dependent anisotropy with light quenching. The data for DCS can be explained by a model which allows wavelength-selective quenching of the long-wavelength emission formed by time-dependent spectral relaxation. These results indicate that polarized light quenching can be used to study systems which display multiple emissions and/or time-dependent spectral shifts.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...