New sensitive and selective calixarene-based fluorescent sensors for the detection of Cs+ in an organoaqueous medium†
Herein, new fluorescent sensors based on calixarene-biscrown-6 containing extended coumarin as a fluorophore were synthetized and their photophysical properties were characterized. These compounds display intense absorption and emission spectra in the visible region due to extension of the coumarin system. Moreover, complexation properties of these ligands were reported, and the Calix-COU-Benz-CN ligand was able to selectively detect cesium ions in an organoaqueous solvent. Upon the addition of cesium, a blue-shift in the absorption spectra and an enhancement of the emission spectra were observed. This ligand was incorporated in a microfluidic device for the detection of Cs+ ions, and a detection limit of 1.4 μM was achieved for these ions.