Photophysics and Fluorimetric Titrations of Fluorescent Ion Indicators |
| |
Authors: | Noël Boens Els Cielen Kristof Van Werde Frans C De Schryver |
| |
Institution: | (1) Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, 3001 Heverlee, Belgium |
| |
Abstract: | A test based on time-resolved fluorescence experiments (Anal. Biochem.
245, 28–37, 1997) allows one to assess the interference of the excited-state association with the fluorimetric determination of the ground-state dissociation constant K
d of fluorescent ion:indicator complexes. If an inflection point occurs in the plot of the fluorescence signal vs – logion] in the ion concentration range where both decay times are invariant, this inflection point can be associated with the correct K
d. Here we apply this test to the fluorescent ion indicators SBFO (for Na+), Mag-fura-2 (for Mg2+), and APTRA-BTC (for Ca2+). In all three cases the decay times are invariant in the concentration ranges of the respective ions where the fluorescence titrations show unique inflection points, indicating that the fluorimetrically determined K
d values are the true K
d values. |
| |
Keywords: | Fluorescence titration fluorescent ion indicator decay time analysis Mag-fura-2 SBFO APTRA-BTC |
本文献已被 SpringerLink 等数据库收录! |
|