TY  - JOUR
A1  - Schwarze, Thomas
A1  - Riemer, Janine
A1  - Holdt, Hans-Jürgen
T1  - A Ratiometric Fluorescent Probe for K+ in Water Based on a Phenylaza-18-Crown-6 Lariat Ether
JF  - Chemistry - a European journal
N2  - This work presents two molecular fluorescent probes 1 and 2 for the selective determination of physiologically relevant K+ levels in water based on a highly K+/Na+ selective building block, the o-(2-methoxyethoxy)phenylaza-18-crown-6 lariat ether unit. Fluorescent probe 1 showed a high K+-induced fluorescence enhancement (FE) by a factor of 7.7 of the anthracenic emission and a dissociation constant (K-d) value of 38mm in water. Further, for 2+K+, we observed a dual emission behavior at 405 and 505nm. K+ increases the fluorescence intensity of 2 at 405nm by a factor of approximately 4.6 and K+ decreases the fluorescence intensity at 505nm by a factor of about 4.8. Fluorescent probe 2+K+ exhibited a K-d value of approximately 8mm in Na+-free solutions and in combined K+/Na+ solution a similar K-d value of about 9mm was found, reflecting the high K+/Na+ selectivity of 2 in water. Therefore, 2 is a promising fluorescent tool to measure ratiometrically and selectively physiologically relevant K+ levels.
KW  - charge transfer
KW  - crown compounds
KW  - fluorescence
KW  - potassium
KW  - ratiometric sensors
Y1  - 2018
U6  - https://doi.org/10.1002/chem.201802306
SN  - 0947-6539
SN  - 1521-3765
VL  - 24
IS  - 40
SP  - 10116
EP  - 10121
PB  - Wiley-VCH
CY  - Weinheim
ER  -