The blue light passing through the phosphor experiences the Stokes shift
down conversion and appears as white light.
Maximum emission wavelength along with full width at half maximum (fwhm) and the Stokes shift
values of the polyoxadiazoles I and copolyoxadiazoles II are collected in Table 1.
However, they have a very small Stokes shift
(Goze et al.
Fluorescein has a relatively small Stokes shift
of approximately 20 nm, and as can be seen in Fig.
(the difference between peak absorption and peak emission wavelength/color) and quantum yield (essentially, how efficient the fluorophore is, or what percentage of absorbed photons generate emitted photons).
emis] (a) Code (mol:mol) (nm) (nm) PA1 1:0 480 -- PA2 1:0 nd -- PA3 1:0 485 -- PA4 1:0 509 -- PA1 1:1 502 +22 PA2 1:1 484 -- PA3 1:1 525 +40 PA4 1:1 -- (b) -- PA1 1:2 499 +19 PA2 1:2 487 -- PA3 1:2 531 +46 PA4 1:2 519 +10 PA1 1:3 506 +26 PA2 1:3 490 -- PA3 1:3 529 +44 PA4 1:3 521 +12 (a) Stokes shift
of undoped and doped PAs in DMA solution.
Using a fluorophore instead of a visual latex bead has many advantages, including the potential for dyes that have a sufficiently large Stokes shift
to prevent fluorescent material that may be in biological samples from giving a false signal in the assay.
It is known that aromatic amines possessing a strong donor and acceptor substituent often exhibit intramolecular charge transfer properties with a large Stokes shift
or dual fluorescence.
Therefore, different fluorescent molecules have different excitation and emission values; this difference is called stokes shift
Fluorophores with sufficiently large Stokes shifts
prevent interference from naturally fluorescent compounds found in biological samples.
They exhibit relatively large Stokes shifts
(~110 nm), and are suitable for multicolor labeling experiments.
Fluorescent europium chelates exhibit large Stokes shifts
(~290 nm) with no overlap between the excitation and emission spectra.