Naphthylhydrazone based selective and sensitive chemosensors for Cu~(2+) and their application in bioimaging

摘要

Two new hydroxynaphthyl-hydrazone based fluorogenic chemosensors R ~1 and R ~2 have been synthesized by Schiff base condensation of Tris(4-formylphenyl)amine with 1-hydroxynaphthalene-2-hydrazide and 1-hydroxynaphthalene-2-carbohydrazone, respectively. They are examined as highly selective and sensitive receptors for Cu ~(2+) ions in aqueous medium. Electronic absorption as well as fluorescence titration studies of receptors R ~1 and R ~2 with different metal cations in H_2O/CH_3CN medium showed highly selective and very rapid (<2 min) binding affinity towards Cu~(2+) ions even in the presence of other commonly coexisting metal ions such as Na ~+, K ~+, Mg ~(2+), Ca ~(2+), Mn ~(2+), Fe ~(2+), Co ~(2+), Ni ~(2+), Zn ~(2+), Cd ~(2+) and Hg ~(2+). Quantification of the fluorescence titration analysis indicated that these newly synthesized receptors (R ~1 and R ~2) can indicate the presence of Cu ~(2+) ions even at very low concentrations of 598 and 676 ppt, respectively. In addition, the propensity of these receptors as bio-imaging fluorescent probes to detect Cu ~(2+) ions in human cervical HeLa cancer cell lines and their cytotoxicity against HeLa cells have been investigated.