A Highly Selective Turn-On Fluorescent Probe for the Detection of Zinc

Abstract

A novel turn-on fluorescence probe L has been designed that exhibits high selectivity and sensitivity with a detection limit of 9.53 × 10−8 mol/L for the quantification of Zn2+. 1H-NMR spectroscopy and single crystal X-ray diffraction analysis revealed the unsymmetrical nature of the structure of the Schiff base probe L. An emission titration experiment in the presence of different molar fractions of Zn2+ was used to perform a Job’s plot analysis. The results showed that the stoichiometric ratio of the complex formed by L and Zn2+ was 1:1. Moreover, the molecular structure of the mononuclear Cu complex reveals one ligand L coordinates with one Cu atom in the asymmetric unit. On adding CuCl2 to the ZnCl2/L system, a Cu-Zn complex was formed and a strong quenching behavior was observed, which inferred that the Cu2+ displaced Zn2+ to coordinate with the imine nitrogen atoms and hydroxyl oxygen atoms of probe L.

Enhanced Luminescence in Zn+2-Induced Au14 Nanocluster Aggregates

“…DPA binds to the core of Au NCs through the −SH moiety, and the free −COOH group is present outside the NC surface. We used various metal ions to see the coordination complexation formation between nanoclusters and metal ions (Figure S3), and a significant PL enhancement is obtained in the presence of Zn 2+ , indicating the strong coordination binding of Zn ions with the carboxylate heads of DPA ligands . Zn 2+ ions lack the ligand field stabilization energy due to their 3d 10 4s 0 electronic configuration.…”

AIE -active TPA modified Schiff base for successive sensing of Cu2+ and His via an on–off–on method and its application in bioimaging

“…Owing to the d 9 electron configuration of Cu 2+ , the excited electrons transferred to the unfilled d-orbital of Cu 2+ instead of returning to the ground state of the ligand in the resultant Cu( ii ) complex, thereby activating non-radiative processes (intersystem crossing). 20,21 However, the concentration of HL decreased with the coordination of Cu 2+ , and the amount of HL aggregates dwindled in the detection system, hence lowering emission intensity. With the further addition of 0.2–0.5 equiv.…”

“…This optical signal amplification effect makes them suitable for constructing “turn-off” fluorescence probes. Considering the paramagnetic quenching effect of Cu 2+ 20,21 and the large affinity of His with Cu 2+ , 13,22 we aim to develop an AIE-active fluorescence probe for the sequential identification of Cu 2+ and His.…”

The importance of spodium bonds, H-bonds and π-stacking interactions in the solid state structures of four zinc complexes with tetradentate secondary diamine ligands

“…[24][25][26] In the presence of different nitro-aromatics, the fluorescence intensity of these zinc complexes is quenched to a considerable extent, and this turn-off florescence response helps the detection of nitroaromatic explosives. [27][28][29][30] From an inorganic chemist's point of view, zinc does not have any preference for a particular geometry (as a result of its d 10 electronic configuration) and therefore it may have varieties of coordination geometries, e.g. tetrahedral, [31][32][33][34][35][36] trigonal bipyramidal, 37,38 square pyramidal, 39,40 octahedral, 41,42 trigonal dodecahedral, 43 etc.…”