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. Issue 44 (17th September 2013)

• Record Type: Journal Article
• Authors: Ast, Sandra; Schwarze, Thomas; Müller, Holger; Sukhanov, Aleksey; Michaelis, Stefanie; Wegener, Joachim; Wolfbeis, Otto S.; Körzdörfer, Thomas; Dürkop, Axel; Holdt, Hans‐Jürgen
• Is Part Of: Chemistry. Volume 19:Issue 44(2013)
• Page Start: 14911
• Page End: 14917
• Publication Date: 2013-09-17
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201302350
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Herein, we report the synthesis of two phenylaza‐[18]crown‐6 lariat ethers with a coumarin fluorophore (<bold>1</bold> and <bold>2</bold>) and we reveal that compound <bold>1</bold> is an excellent probe for K⁺ ions under simulated physiological conditions. The presence of a 2‐methoxyethoxy lariat group at the <italic>ortho</italic> position of the anilino moiety is crucial to the substantially increased stability of compounds <bold>1</bold> and <bold>2</bold> over their lariat‐free phenylaza‐[18]crown‐6 ether analogues. Probe <bold>1</bold> shows a high K⁺/Na⁺ selectivity and a 2.5‐fold fluorescence enhancement was observed in the presence of 100 m<sc>M</sc> K⁺ ions. A fluorescent membrane sensor, which was prepared by incorporating probe <bold>1</bold> into a hydrogel, showed a fully reversible response, a response time of 150 s, and a signal change of 7.8 % per 1 m<sc>M</sc> K⁺ within the range 1–10 m<sc>M</sc> K⁺. The membrane was easily fabricated (only a single sensing layer on a solid polyester support), yet no leaching was observed. Moreover, compound <bold>1</bold> rapidly permeated into cells, was cytocompatible, and was suitable for the fluorescent imaging of K⁺ ions on both the extracellular and intracellular levels.</p> </abstract>