Principles of Fluorescence Spectroscopy

884 APPENDIX II P FLUORESCENCE LIFETIME STANDARDS
Figure II.2. PPD in ethanol as a single-decay-time standard, in
ethanol in equilibrium with air. Reprinted with permission from [2].
Copyright © 1990, American Institute of Physics.
2. PICOSECOND LIFETIME STANDARDS
Derivatives of dimethylamino-stilbene were characterized
as lifetime standards with subnanosecond lifetimes 3 (Figure
II.3). Excitation wavelengths range up to 420 nm, and emission
wavelengths from 340 to over 500 nm (Figure II.4).
Figure II.3. Picosecond lifetime standard fluorophores. From [3].
Figure II.4. Top: Absorption and fluorescence spectra of DMS in
cyclohexane (solid) and N,N'-dimethylformamide (dashed) at 25°C.
Middle: Absorption and fluorescence spectra of DFS (solid) and DBS
(dashed) in cyclohexane at 25°C. Bottom: Absorption and fluorescence
spectra of DCS in cyclohexane (solid) and toluene (dashed) at
25°C. Revised from [3].
Figure II.5. Representative frequency response of the picosecond lifetime
standards. From [3].