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A dipodal ligand 2,2′-((ethane-1,2-diylbis(azanediyl))bis(ethane-1,1-diyl))diphenol was synthesized through a condensation reaction and was characterized with IR, 1H NMR, 13C-NMR, and mass spectroscopy. The receptor 2 has shown marked enhancement in fluorescence intensity (emission signal at 341 nm) on binding with Zn2+ as compared to other surveyed metal ions. The sensor has shown dramatic changes in dual channel fluorescence emission with λmax at 300 and 341 nm. The successive addition of Zn2+ to the solution of the sensor led to a blue shift of the peak maxima and interestingly upon addition of higher equivalents of Zn2+ quenched the fluorescence intensity of the sensor, and ultimately the original fluorescent profile of sensor was restored. The structures of 2 and 3 were optimized with B3LYP/LanL2DZ basis sets. The receptor 2 successfully detect the Zn2+ ion in HeLa cells cultured in Zn2+ enriched medium. [ABSTRACT FROM AUTHOR]

A colorimetric and fluorescent 'on-off' chemosensor 1 was developed for the selective and sensitive detection of Cu2+ over the other examined metal ions. Upon addition of Cu2+, sensor 1 exhibits moderate enhancement in the absorbance intensity with a naked-eye detectable colour change from colourless to yellow in DMSO/H2O (50:50, v/v). Also, the emission of 1 was selectively quenched in the presence Cu2+ with fast response and the detection limit was found to be 50 nM. [ABSTRACT FROM AUTHOR]

A fluorescent based receptor (4Z)-4-(4-diethylamino)-2-hydroxybenzylidene amino)-1,2dihydro-1,5-dimethyl-2-phenylpyrazol-3-one (receptor 3 ) was developed for the highly selective and sensitive detection of Cu 2+ and Zn 2+ in semi-aqueous system. The fluorescence of receptor 3 was enhanced and quenched, respectively, with the addition of Zn 2+ and Cu 2+ ions over other surveyed cations. The receptor formed host-guest complexes in 1:1 stoichiometry with the detection limit of 5 nM and 15 nM for Cu 2+ and Zn 2+ ions, respectively. Further, we have effectively utilized the two metal ions (Cu 2+ and Zn 2+ ) as chemical inputs for the manufacture of INHIBIT type logic gate at molecular level using the fluorescence responses of receptor 3 at 450 nm. [ABSTRACT FROM AUTHOR]

Abstract: A malonohydrazide derivative bearing an imine and phenolic group was synthesized and had a high affinity and selectivity towards Zn2+. The recognition properties of receptor 1 were evaluated using absorbance and fluorescence spectroscopy. The 1:1 stoichiometry of 1.Zn2+ was confirmed from job׳s plot, mass spectra and density functional theory (DFT). The detection of Zn2+ in intracellular environment of HeLa cell through confocal microscopy was successfully applied for live cell imaging. [Copyright &y& Elsevier]