Premium
A Highly K + ‐Selective Two‐Photon Fluorescent Probe
Author(s) -
Schwarze Thomas,
Riemer Janine,
Eidner Sascha,
Holdt HansJürgen
Publication year - 2015
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201501473
Subject(s) - fluorescence , two photon excitation microscopy , photon , chemistry , physics , radiochemistry , atomic physics , photochemistry , optics
Abstract A highly K + ‐selective two‐photon fluorescent probe for the in vitro monitoring of physiological K + levels in the range of 1–100 m M 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 m M 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) m M and K d TP =(36±6) m M ) and in combined K + /Na + solutions ( K d OP =(38±8) m M and K d TP =(46±25) m M ) reflecting the high K + /Na + selectivity of the fluorescent probe. The TP absorption cross‐section ( σ 2PA ) of the TPEF probe+160 m M K + is 26 GM at 860 nm. Therefore, the TPEF probe is a suitable tool for the in vitro determination of K + .