Nanomolar fluorogenic recognition of Cu(II) in aqueous medium-A highly selective on-off probe based on mesitylene derivative

A mesitylene based tripodal Schiff s base, 2,2',2 ''-((1E,1'E,1 '' E)-(((((2,4,6-trimethylbenzene-1,3,5-triy1) tris(methylene))tris(sulfanediyl))tris-(benzene-2,1-diyl))tris(azanylylidene))tris(methanylylidene))tris (4-nitrophenol), with -OH as end groups has been synthesized and characterized by spectroscopic methods. The compound has been found to act as a highly sensitive (up to 3.16 nM) and selective, fluorogenic sensor toward Cu(II) ions, in aqueous medium. The fluorescence emission spectra of the sensor showed a band at 528 nm due to ESIPT phenomenon which gets quenched up to 94% in the presence of Cu(II) ions. The sensor has been shown to have no cytotoxic effect, hence can be conveniently used in biological systems as well. (C) 2013 Elsevier B.V. All rights reserved.