TY  - JOUR
A1  - Schwarze, Thomas
A1  - Riemer, Janine
T1  - Highly K+ selective probes with fluorescence emission wavelengths higher than 500 nm in water
T2  - ChemistrySelect
N2  - Herein, we report on the synthesis of highly K+/Na+ selective fluorescent probes in a feasible number of synthetic steps. These K+ selective fluorescent probes, so called fluoroionophores, 1 and 2 consists of different highly K+/Na+ selective building blocks the alkoxy-substituted N-phenylaza-18-crown-6 lariat ethers (ionophores) and "green" (cf. coumarin unit in 1) or "red" (cf. nile red unit in 2) fluorescent moieties (fluorophores). The fluorescent probes 1 and 2 show K+ induced fluorescence enhancement factors of 4.1 for 1 and 1.9 for 2 and dissociation constants for the corresponding K+ complexes of 43 mM (1+K+) and 18 mM (2+K+) in buffered aqueous solution. The fluorescence signal of 1 and 2 is changed by less than 5 % by pH values in the range of 6.8 to 8.8. Thus, 1 and 2 are capable fluorescent tools to determine extracellular K+ levels by fluorescence enhancements at wavelengths higher than 500 nm.
KW  - potassium
KW  - sodium
KW  - fluorescence
KW  - selectivity
KW  - probes
Y1  - 2020
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/57340
SN  - 2365-6549
VL  - 5
IS  - 42
SP  - 13174
EP  - 13178
PB  - Wiley-VCH
CY  - Weinheim
ER  -