TY  - JOUR
A1  - Schwarze, Thomas
A1  - Riemer, Janine
A1  - Eidner, Sascha
A1  - Holdt, Hans-Jürgen
T1  - A Highly K+-Selective Two-Photon Fluorescent Probe
JF  - Chemistry - a European journal
N2  - A highly K+-selective two-photon fluorescent probe for the in vitro monitoring of physiological K+ levels in the range of 1-100 mM is reported. The two-photon excited fluorescence (TPEF) probe shows a fluorescence enhancement (FE) by a factor of about three in the presence of 160 mM K+, independently of one-photon (OP, 430 nm) or two-photon (TP, 860 nm) excitation and comparable K+-induced FEs in the presence of competitive Na+ ions. The estimated dissociation constant (K-d) values in Na+-free solutions (K-d(OP)=(28 +/- 5) mM and K-d(TP)=(36 +/- 6) mM) and in combined K+/Na+ solutions (K-d(OP)=(38 +/- 8) mM and K-d(TP)=(46 +/- 25) mM) reflecting the high K+/Na+ selectivity of the fluorescent probe. The TP absorption cross-section (sigma(2PA)) of the TPEF probe+160 mMK(+) is 26 GM at 860 nm. Therefore, the TPEF probe is a suitable tool for the in vitro determination of K+.
KW  - click chemistry
KW  - fluorescence
KW  - fluorescent probes
KW  - potassium
KW  - two-photon
Y1  - 2015
U6  - https://doi.org/10.1002/chem.201501473
SN  - 0947-6539
SN  - 1521-3765
VL  - 21
IS  - 32
SP  - 11306
EP  - 11310
PB  - Wiley-VCH
CY  - Weinheim
ER  -