A highly selective, sensitive and reversible fluorescence chemosensor for Zn²⁺ and its cell viability

Abstract

A new imine conjugate Schiff base ligand (H2L) was prepared and evaluated for its sensing properties. H2L detects Zn2+ selectively among the wide range of metal ions. The sensing behavior of H2L was identified by UV-vis, fluorescence and 1H NMR titration. H2L shows fluorescence switch ON with the Zn2+ ion among 18 other metal/heavy metal ions with a detection limit of 1.47 μM. The binding of Zn2+ was confirmed by single crystal X-ray studies, which reveal the formation of binuclear complex (1). The packing diagram of H2L reveals the presence of rare linear C–H⋯C interactions (bond distance 2.79 Å and bond angle 180°) which form 1D-polymeric chains. Furthermore, the cytotoxicity of H2L and 1 has been assessed against MCF-7 and A375 cell lines and both are found to have marginal toxicity.

Selective Detection of Picric Acid and Pyrosulfate Ion by Nickel Complexes Offering a Hydrogen-Bonding-Based Cavity

“…The marginally different emission spectral features are most probably due to the involvement of very similar ligands that only differed by the appended heterocyclic rings. ,, The Stokes shift (nm) for complexes 1 , 2 , and 3 was found to be 46, 44, and 32, respectively . The fluorescence quantum yield for complexes 1 , 2 , and 3 was 0.082, 0.096, and 0.073, respectively. , We also evaluated the stability for all three nickel complexes in CH 3 CN/H 2 O (1:1) for 6 h by using emission spectroscopy (Figure S7). In all three cases, insignificant changes in the emission intensity with time asserted their stable nature for sensing studies.…”

“…57 The fluorescence quantum yield for complexes 1, 2, and 3 was 0.082, 0.096, and 0.073, respectively. 58,59 We also evaluated the stability for all three nickel complexes in CH 3 CN/H 2 O (1:1) for 6 h by using emission spectroscopy (Figure S7). In all three cases, insignificant changes in the emission intensity with time asserted their stable nature for sensing studies.…”

The development of fluorescence turn-on probe for Al(III) sensing and live cell nucleus-nucleoli staining

“…We recently reported synthesis of a highly selective, sensitive and reversible symmetric chemosensor H 2 L for Zn 2+ ion ( Supplementary Fig. S1 ) 30 . Encouraged by the results, we have slightly altered the ratio of 2,4,6-trimethylbenzene-1,3-diamine and 2-Hydroxy-1-napyhaldehyde to 1:1 ( Fig.…”

“…The emission studies of L 1 at excitation wavelength 309 nm, shows weak fluorescence at 341 nm which is attributed to the isomerization of the imine bond (−HC=N) and excited state intramolecular proton transfer (ESIPT) from the −OH group to the imine nitrogen 30 . The titration of L 1 with Al 3+ shows gradual fluorescence enhancement with a bathochromic shift (red shift) of 2 nm having maximum fluorescence intensity at 343 nm.…”

An aminoquinoline based fluorescent probe for sequential detection of Znic (II) and inorganic phosphate and application in living cell imaging

“…Znic, as the second most abundant transition metal ion in the human body after iron, plays a significant role in majority of biological processes, such as regulation of metalloenzyme, gene transcription and protein expression, neural signal transmission and apoptosis . At the same time, Zn 2+ is as well responsible for the immune system so that zinc deficiency poses to increased organism susceptibility to pathogens and the abnormal accumulation of Zn 2+ has been observed in brain tissue affected by neurodegenerative diseases.…”