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

Abstract

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.

Metal‐Cation Recognition in Water by a Tetrapyrazinoporphyrazine‐Based Tweezer Receptor

“…(1,4,7-trioxa-10-azacyclododecan-10-yl) 9, 70.1, 70.6, 71.9, 116.0, 119.8, 147.4 ppm;I R( ATR): ñ = 2961, 2908, 2869, 2229(CN), 2176, 1931, 1701, 1654, 1518, 1485, 1448, 1420, 1389, 1378, 1359, 1344, 1297, 1273, 1255, 1240, 1219, 1155, 1131, 1116, 1107, 1096, 1058, 1039, 1007 ;e lemental analysis calcd (%) for C 22 H 32 N 6 O 6 :C55.45,H6 .77,N1 7.64;found:C55.32,H6 .80,N1 7.50. 5,4,7,pyrazine-2,3-dicarbonitrile (3 b):5 ,6-Dichloropyrazine-2,3-dicarbonitrile (500 mg, 2.51 mmol), 1-aza [15]crown-5 (1.16 g, 5.29 mmol), anhydrous K 2 CO 3 (1.73 g, 12.56 mmol), reaction time 4h,e luent:c hloro-…”

“…Cation binding by various synthetic receptors derived from crown ethers has been of interest in host–guest chemistry since the discovery of crown ethers by Pedersen in 1967 . Suitable supramolecular arrangements of crown ether analogues (such as cryptands,coronands, and lariat ethers) may provide an incredible tool for selective cation recognition. Among them, the tweezer (occasionally also called sandwich or clamshell) arrangement of two crown units has been shown to substantially increase the stability of the complex (i.e., association constant) and improve selectivity towards specific analytes .…”

Potassium‐Ion‐Selective Fluorescent Sensors To Detect Cereulide, the Emetic Toxin of B. cereus, in Food Samples and HeLa Cells

“…Because cereulide is not soluble in water,arequisite of the fluorogenic probe is that it have good performance in organic or mixed organic-aqueous solvents. Therefore, we selected ap erylenemonoimidea st he fluorescentr eporter [12] and aK + -selective phenylaza[18]crown-6-lariat-ether [13] or at riazacryptand [14] as the recognition units and bonded both moieties in every case by Suzuki coupling (Scheme 1).…”

New Nanomaterials and Luminescent Optical Sensors for Detection of Hydrogen Peroxide

“…This could be achieved by using copolymers containing nonpolar domains (for particle embedding) and polar domains to allow a rapid access for hydrogen peroxide. Hypan HN80 [42] is a polyacrylamidepolyacrylonitrile copolymer that should be useful for this purpose. It contains hard (polyacrylonitrile domains, lipophilic) and soft blocks (polyacrylamide domains, hydrophilic).…”