Copper ion luminescence on/off sensing by a quinoline-appended ruthenium(II)-polypyridyl complex in aqueous media

An efficient chemosensor RuL based on a quinoline tethered Ru (bpy)(2)(2+) derivative is developed for Cu2+ ion detection in pure aqueous medium. Receptor RuL has been characterized using standard spectral studies including UV-visible, fluorescence, ESI-MS and H-1 NMR techniques. The crystal structure of RuL is determined by X-ray diffraction studies which revealed that Ru(II) is coordinated to nitrogen atoms of phenanthroline moiety. However N atoms of quinoline and imidazole units are uncoordinated and freely accessible for further functionalization. Changes in photochemical properties of RuL, high selectivity, reversibility by EDTA, excellent detection limit (50.67 nM) and high binding parameters displayed excellent sensing ability for Cu2+ ion. This work illustrates application of a water-soluble receptor in excellent sensing of cupric ion. (C) 2019 Elsevier B.V. All rights reserved.