TY - JOUR
T1 - Background-Free Fluorescence-Decay-Time Sensing and Imaging of pH with Highly Photostable Diazaoxotriangulenium Dyes
AU - Dalfen, Irene
AU - Dmitriev, Ruslan I.
AU - Holst, Gerhard
AU - Klimant, Ingo
AU - Borisov, Sergey M.
PY - 2019/1/2
Y1 - 2019/1/2
N2 - Novel fluorescent diazaoxatriangulenium (DAOTA) pH indicators for lifetime-based self-referenced pH sensing are reported. The DAOTA dyes were decorated with phenolic-receptor groups inducing fluorescence quenching via a photoinduced-electron-transfer mechanism. Electron-withdrawing chlorine substituents ensure response in the most relevant pH range (apparent pKa values of ∼5 and 7.5 for the p,p-dichlorophenol- and p-chlorophenol-substituted dyes, respectively). The dyes feature long fluorescence lifetimes (17-20 ns), high quantum yields (∼60%), and high photostabilities. Planar optodes are prepared upon immobilization of the dyes into polyurethane hydrogel D4. Apart from the response in the fluorescence intensity, the optodes show pH-dependent lifetime behavior, which makes them suitable for studying 2D pH distributions with the help of fluorescence-lifetime-imaging techniques. The lifetime response is particularly pronounced for the sensors with high dye concentrations (0.5-1 wt % with respect to the polymer) and is attributed to the efficient homo-FRET mechanism.
AB - Novel fluorescent diazaoxatriangulenium (DAOTA) pH indicators for lifetime-based self-referenced pH sensing are reported. The DAOTA dyes were decorated with phenolic-receptor groups inducing fluorescence quenching via a photoinduced-electron-transfer mechanism. Electron-withdrawing chlorine substituents ensure response in the most relevant pH range (apparent pKa values of ∼5 and 7.5 for the p,p-dichlorophenol- and p-chlorophenol-substituted dyes, respectively). The dyes feature long fluorescence lifetimes (17-20 ns), high quantum yields (∼60%), and high photostabilities. Planar optodes are prepared upon immobilization of the dyes into polyurethane hydrogel D4. Apart from the response in the fluorescence intensity, the optodes show pH-dependent lifetime behavior, which makes them suitable for studying 2D pH distributions with the help of fluorescence-lifetime-imaging techniques. The lifetime response is particularly pronounced for the sensors with high dye concentrations (0.5-1 wt % with respect to the polymer) and is attributed to the efficient homo-FRET mechanism.
UR - http://www.scopus.com/inward/record.url?scp=85059638759&partnerID=8YFLogxK
U2 - 10.1021/acs.analchem.8b02534
DO - 10.1021/acs.analchem.8b02534
M3 - Article
C2 - 30518209
AN - SCOPUS:85059638759
SN - 0003-2700
VL - 91
SP - 808
EP - 816
JO - Analytical Chemistry
JF - Analytical Chemistry
IS - 1
ER -