β-Cyclodextrin included coumarin derivatives as selective fluorescent sensors for Cu2+ ions in HeLa cells

摘要

A highly sensitive and selective fluorescent sensor for Cu ~(2+) ions in water medium is reported using 4-((benzo[ d ]thiazol-2-ylthio)methyl)-5,7-dihydroxy-2 H -chromen-2-one ( 1 ) included β-cyclodextrin, as a probe. The fluorogenic supramolecule has displayed good selectivity and affinity towards Cu ~(2+) ions over other cations after examining in biological systems with intracellular Cu ~(2+) ions, especially in cultured HeLa cells using fluorescence microscopic imaging. The lowest detection limit of Cu ~(2+) ions observed using this probe is as low as 2.52 × 10 ~(?10) M. The observed on-off fluorescence with the periodic addition of Cu ~(2+) ion is explained via an Intramolecular Charge Transfer mechanism (ICT) and the inclusion of 1 in β-cyclodextrin is characterised by ~(1) H-NMR molecular modeling studies. The results show that the present β-CD: 1 system, studied in HeLa cells, can be potentially used in monitoring the biological functions of Cu ~(2+) ions.