Effect of protons and metal ions on the fluorescence properties of a polylysin dendrimer containing twenty four dansyl units †

2000 ◽  
pp. 3765-3771 ◽  
Author(s):  
Vincenzo Balzani ◽  
Paola Ceroni ◽  
Sven Gestermann ◽  
Marius Gorka ◽  
Christopher Kauffmann ◽  
...  
Keyword(s):  
Metal Ions ◽  
Fluorescence Properties

Synthesis of highly fluorescent gold nanoclusters and their use in sensitive analysis of metal ions

The Analyst ◽  
2017 ◽  
Vol 142 (23) ◽  
pp. 4486-4493 ◽  
Author(s):  
Yayu Yang ◽  
Ailing Han ◽  
Ruixue Li ◽  
Guozhen Fang ◽  
Jifeng Liu ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Metal Ions ◽  
Gold Nanoclusters ◽  
Emission Peak ◽  
Fluorescence Properties ◽  
Sensitive Analysis ◽  
The Core ◽  
Au Clusters

The fluorescence properties, including emission peak and quantum yield, of Au clusters are dependent upon the ligands capping the core.

Spectroscopic Characterization of the Artificial Siderophore Pyridinochelin

2006 ◽  
Vol 61 (9-10) ◽  
pp. 741-748 ◽  
Author(s):  
Michael U. Kumke ◽  
Carsten Dosche ◽  
Roman Flehr ◽  
Wolfram Trowitzsch-Kienast ◽  
Hans-Gerd Löhmannsröben
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Fluorescence Probe ◽  
Fluorescence Decay ◽  
Molecular Probes ◽  
Transport Processes ◽  
Intrinsic Fluorescence ◽  
Fluorescence Properties ◽  
Free Form ◽  
Fluorescence Characteristics

AbstractSiderophores play a very important role in the uptake process of iron by bacteria. Due to the so-called active transport the uptake of siderophores by bacteria is very specific, which makes the use of siderophores as effective shuttles for antibiotics in the treatment of infections and other diseases caused by bacteria highly attractive. In order to further investigate the transport and incorporation of siderophores into the bacteria cells, distinct molecular probes are needed. Especially artificial siderophores, that show a specific intrinsic fluorescence, are highly attractive for such monitoring purposes. A promising candidate of such a fluorescent artificial siderophore is bis-2,3-dihydroxybenzoyl-2,6-dimethylamino-pyridine (pyridinochelin, PY). The fluorescence properties of PY were investigated in different solvents and in the presence of different metal ions. It was found that PY in its free form shows a complex fluorescence behavior. In methanol a clear dual fluorescence is observed. In aqueous solution intermolecular interactions with water molecules are determining the intrinsic fluorescence. Upon complexation with metal ions (Me3+ = Eu3+, Tb3+, Al3+, Fe3+) the fluorescence characteristics changed. The fluorescence quantum yield of PY decreased upon addition of Me3+ - except for Al3+, which showed no fluorescence quenching. The fluorescence decay of PY loaded with metal ions showed a nicely mono-exponential fluorescence decay, which was in contrast to PY in the absence of metal ions. This drastic change in the fluorescence properties of PY upon metal ion complexation makes PY highly attractive as a fluorescence probe for the investigation of siderophore action and siderophore-mediated transport processes

scholarly journals Fluorescence properties of Neurospora tyrosinase

1982 ◽  
Vol 205 (1) ◽  
pp. 173-180 ◽  
Author(s):  
M Beltramini ◽  
K Lerch
Keyword(s):  
Quantum Yield ◽  
Fluorescence Spectroscopy ◽  
Metal Ions ◽  
Fluorescent Probe ◽  
Active Site ◽  
Emission Intensity ◽  
Marked Decrease ◽  
Emission Spectra ◽  
Fluorescence Properties ◽  
Tryptophan Residues

Some structural properties of Neurospora tyrosinase have been studied by fluorescence spectroscopy. The emission spectra observed for oxy-, deoxy-, met- and apo-tyrosinase and the Co2+-substituted form are indicative of a protein containing buried tryptophan residues. By using acrylamide and iodide, part of the emission is quenched, indicating heterogeneity in the tryptophan environment. Upon binding of Cu2+ or Co2+ to apo-tyrosinase, a marked decrease of the tryptophan quantum yield is observed. A further decrease in emission intensity results from the binding of molecular O2 to the deoxy form. The fluorescent probe 8-anilinonaphthalene-1-sulphonate binds to tyrosinase only when the metal ions are removed. Reconstitution of apo-tyrosinase with Cu2+ completely displaces the probe, suggesting that 8-anilinonaphthalene-1-sulphonate binds to apo-tyrosinase at the active site. The fluorescence properties of Neurospora tyrosinase are compared with those of haemocyanin.

Assembly of ZnIIand CdIIcoordination polymers based on a flexible multicarboxylate ligand and nitrogen-containing auxiliary ligands through a mixed-ligand synthetic strategy: syntheses, structures and fluorescence properties

2016 ◽  
Vol 72 (2) ◽  
pp. 99-104 ◽  
Author(s):  
Ji-Tao Lu ◽  
Dan-Dan Meng ◽  
Qing-Guo Meng
Keyword(s):  
Metal Ions ◽  
Coordination Polymers ◽  
Mixed Ligand ◽  
Fluorescence Properties ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Synthetic Strategy ◽  
Layer Structures ◽  
Weak Hydrogen Bonds

The structures of coordination polymers are strongly influenced by the organic ligands and metal ions used for their construction, so it is important to choose suitable ligands and metal ions and appropriate synthetic processes. Two noveld10coordination polymers, namely poly[[diaquabis(2,2′-bipyridine)[μ4-4,4′-(1,4-phenylenedioxy)bis(benzene-1,2-dicarboxylato)]dizinc(II)] dihydrate], {[Zn2(C22H10O10)(C10H8N2)2(H2O)2]·2H2O}n, (1), and poly[[diaquabis(1,10-phenanthroline)[μ4-4,4′-(1,4-phenylenedioxy)bis(benzene-1,2-dicarboxylato)]dicadmium(II)] dimethylformamide disolvate], {[Cd2(C22H10O10)(C12H8N2)2(H2O)2]·2C3H7NO}n, (2), have been synthesized from 4,4′-(1,4-phenylenedioxy)bis(benzene-1,2-dicarboxylic acid) (H4L) and two different N-containing auxiliary ligands through a mixed-ligand synthetic strategy under a solvothermal environment. The structures were characterized by single-crystal X-ray diffraction, powder X-ray diffraction, elemental analysis and IR spectroscopy. Compounds (1) and (2) both present one-dimensional chain structures and two-dimensional supramolecular layer structures constructed by weak hydrogen bonds. It is interesting to note that the carboxylate ligands reveal stabletransconfigurations in both compounds. The fluorescence properties of (1) and (2) in the solid state were also investigated.

HREM Study of electron-induced surface radiation damage in ReO3

1991 ◽  
Vol 49 ◽  
pp. 636-637
Author(s):  
R. Ai ◽  
H.-J. Fan ◽  
L. D. Marks
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Metal Oxides ◽  
Electron Irradiation ◽  
Transition Metal Oxides ◽  
Carbon Film ◽  
Transition Metal Ions ◽  
Surface Radiation ◽  
Valence Transition ◽  
Electron Microscopes

It has been known for a long time that electron irradiation induces damage in maximal valence transition metal oxides such as TiO2, V2O5, and WO3, of which transition metal ions have an empty d-shell. This type of damage is excited by electronic transition and can be explained by the Knoteck-Feibelman mechanism (K-F mechanism). Although the K-F mechanism predicts that no damage should occur in transition metal oxides of which the transition metal ions have a partially filled d-shell, namely submaximal valence transition metal oxides, our recent study on ReO3 shows that submaximal valence transition metal oxides undergo damage during electron irradiation.ReO3 has a nearly cubic structure and contains a single unit in its cell: a = 3.73 Å, and α = 89°34'. TEM specimens were prepared by depositing dry powders onto a holey carbon film supported on a copper grid. Specimens were examined in Hitachi H-9000 and UHV H-9000 electron microscopes both operated at 300 keV accelerating voltage. The electron beam flux was maintained at about 10 A/cm2 during the observation.

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