TY - JOUR A1 - Ast, Sandra A1 - Schwarze, Thomas A1 - Müller, Holger A1 - Sukhanov, Aleksey A1 - Michaelis, Stefanie A1 - Wegener, Joachim A1 - Wolfbeis, Otto S. A1 - Körzdörfer, Thomas A1 - Dürkop, Axel A1 - Holdt, Hans-Jürgen T1 - A highly K+-Selective Phenylaza-[18]crown-6-Lariat-Ether-Based Fluoroionophore and its application in the sensing of K+ Ions with an optical sensor film and in cells JF - Chemistry - a European journal N2 - Herein, we report the synthesis of two phenylaza-[18]crown-6 lariat ethers with a coumarin fluorophore (1 and 2) and we reveal that compound 1 is an excellent probe for K+ ions under simulated physiological conditions. The presence of a 2-methoxyethoxy lariat group at the ortho position of the anilino moiety is crucial to the substantially increased stability of compounds 1 and 2 over their lariat-free phenylaza-[18] crown-6 ether analogues. Probe 1 shows a high K+/Na+ selectivity and a 2.5-fold fluorescence enhancement was observed in the presence of 100 mm K+ ions. A fluorescent membrane sensor, which was prepared by incorporating probe 1 into a hydrogel, showed a fully reversible response, a response time of 150 s, and a signal change of 7.8% per 1 mm K+ within the range 1-10 mm K+. The membrane was easily fabricated (only a single sensing layer on a solid polyester support), yet no leaching was observed. Moreover, compound 1 rapidly permeated into cells, was cytocompatible, and was suitable for the fluorescent imaging of K+ ions on both the extracellular and intracellular levels. KW - crown compounds KW - fluorescence KW - gels KW - potassium KW - sensors Y1 - 2013 U6 - https://doi.org/10.1002/chem.201302350 SN - 0947-6539 SN - 1521-3765 VL - 19 IS - 44 SP - 14911 EP - 14917 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Schwarze, Thomas A1 - Riemer, Janine A1 - Müller, Holger A1 - John, Leonard A1 - Holdt, Hans-Jürgen A1 - Wessig, Pablo T1 - Na+ Selective Fluorescent Tools Based on Fluorescence Intensity Enhancements, Lifetime Changes, and on a Ratiometric Response JF - Chemistry - a European journal N2 - Over the years, we developed highly selective fluorescent probes for K+ in water, which show K+-induced fluorescence intensity enhancements, lifetime changes, or a ratiometric behavior at two emission wavelengths (cf. Scheme 1, K1-K4). In this paper, we introduce selective fluorescent probes for Na+ in water, which also show Na+ induced signal changes, which are analyzed by diverse fluorescence techniques. Initially, we synthesized the fluorescent probes 2, 4, 5, 6 and 10 for a fluorescence analysis by intensity enhancements at one wavelength by varying the Na+ responsive ionophore unit and the fluorophore moiety to adjust different K-d values for an intra- or extracellular Na+ analysis. Thus, we found that 2, 4 and 5 are Na+ selective fluorescent tools, which are able to measure physiologically important Na+ levels at wavelengths higher than 500 nm. Secondly, we developed the fluorescent probes 7 and 8 to analyze precise Na+ levels by fluorescence lifetime changes. Herein, only 8 (K-d=106 mm) is a capable fluorescent tool to measure Na+ levels in blood samples by lifetime changes. Finally, the fluorescent probe 9 was designed to show a Na+ induced ratiometric fluorescence behavior at two emission wavelengths. As desired, 9 (K-d=78 mm) showed a ratiometric fluorescence response towards Na+ ions and is a suitable tool to measure physiologically relevant Na+ levels by the intensity change of two emission wavelengths at 404 nm and 492 nm. KW - crown compounds KW - fluorescence lifetime KW - fluorescent probes KW - ratiometric KW - sodium Y1 - 2019 U6 - https://doi.org/10.1002/chem.201902536 SN - 0947-6539 SN - 1521-3765 VL - 25 IS - 53 SP - 12412 EP - 12422 PB - Wiley-VCH CY - Weinheim ER -