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Phosphorescence is a type of photoluminescence related to fluorescence. When exposed to light (radiation) of a shorter wavelength, a phosphorescent substance will glow, absorbing the light and reemitting it at a longer wavelength. Unlike fluorescence, a phosphorescent material does not immediately reemit the radiation it absorbs.
[1] [2] "Fluorescence microscope" refers to any microscope that uses fluorescence to generate an image, whether it is a simple set up like an epifluorescence microscope or a more complicated design such as a confocal microscope, which uses optical sectioning to get better resolution of the fluorescence image. [3]
A simplified Jablonski diagram illustrating the change of energy levels.. The principle behind fluorescence is that the fluorescent moiety contains electrons which can absorb a photon and briefly enter an excited state before either dispersing the energy non-radiatively or emitting it as a photon, but with a lower energy, i.e., at a longer wavelength (wavelength and energy are inversely ...
The difference here lies in the relative stability of the energized electron. Unlike with fluorescence, in phosphorescence the electron retains stability, emitting light that continues to "glow in the dark" even after the stimulating light source has been removed. [24]
It is neither fluorescence not phosphorescence. [ 2 ] [ 3 ] In fluorescence, the lifetime of the excited state lasts a few nanoseconds. In phosphorescence, even if the emission lives several seconds, this is due to deexcitation between two electronic states of different spin multiplicity .
Fluorescence correlation spectroscopy (FCS) is an analysis technique that observes the fluctuation of fluorescence intensity. This analysis is a component of many fluorescence imaging machines and improvements in spatial resolution could improve the sensitivity and range.
Electrons change energy states by either resonantly gaining energy from absorption of a photon or losing energy by emitting photons. In chemistry-related disciplines, one often distinguishes between fluorescence and phosphorescence. The former is typically a fast process, yet some amount of the original energy is dissipated so that re-emitted ...
Furthermore, tryptophan fluorescence is strongly influenced by the proximity of other residues (i.e., nearby protonated groups such as Asp or Glu can cause quenching of Trp fluorescence). Also, energy transfer between tryptophan and the other fluorescent amino acids is possible, which would affect the analysis, especially in cases where the ...