نتایج جستجو برای: europium
تعداد نتایج: 1945 فیلتر نتایج به سال:
A flow injection (FI) spectrophotometric determination of europium (III) is described, based on the complexation between europium (III), and chlortetracycline (CTC) in a Tris-buffer pH 8.0 medium. The resulting yellow-coloured complex is measured at its absorption maximum of 400 nm after 100 mul of sample or standard solution containing europium (III) are injected into the merged streams of CTC...
In this paper, we report on the luminescence of europium by directly exciting europium ions with visible light in aqueous medium. Upon replacing all the water molecules that coordinate around a central europium ion with a ditopic ligand 1,11-bis(2,6-dicarboxypyridin-4-yloxy)-3,6,9-trioxaundecane (L2EO4), the quenching from water molecules is efficiently eliminated, offering considerable europiu...
This work presents for the first time the electrochemical determination of europium using cyclic voltammetry at gold electrodes modified with 2-pyridinol-1-oxide. A well-defined oxidation peak was observed in cyclic voltammetry as a result of the oxidation of the europium at ∼1100 mV in phosphate buffer at pH 7.0. The peak current increased linearly with the increase of concentration of the eur...
We report the crystal structure at 1 Å resolution of europium bound to diethylenetriaminepentaacetate covalently coupled to an organic chromophore, carbostyril 124 (DTPA-cs124; carbostyril 124 ) 7-amino-4-methyl-2(1H)quinolinone). The complex is highly luminescent in solution and in the crystal form. The Eu-DTPA-cs124 crystallizes in the space group C2/c with two molecules in the asymmetric uni...
Two novel trinuclear europium complexes based on trisphen(1,3,5-tris{4-((1,10-phenanthroline-[5,6-d]imidazol-2yl)phenoxy)methyl}-2,4,6-trimethyl-benzene) as a second ligand were designed, synthesized, and characterized by FT-IR, (1)H NMR, UV-visible, photoluminescence (PL) spectroscopy, elemental analysis (EA) and ESI-MS. The geometries of these two trinuclear europium complexes were predicted ...
Influence of Eu(3+) doping content on antioxidant properties of Lu2O3 sol-gel derived nanoparticles.
This paper presents the synthesis of pure and europium-doped lutetium oxide (Lu2O3) powders prepared by sol-gel method. The influence of europium ion concentration into Lu2O3 nanocrystallites was investigated for first time in an in vitro system using a modified ABTS radical cation decolorization assay to determine the antioxidant activity. The crystalline structure of Lu2O3 and Eu:Lu2O3 powder...
A new fluorescent method was developed based on the ulifloxacin-europium (III)-sodium dodecylbenzene sulfonate system for the determination of ulifloxacin, the active metabolite of prulifloxacin. Sodium dodecylbenzene sulfonate formed a ternary complex with ulifloxacin-europium (III) and significantly enhaneed the characteristic fluorescence of europium (III). The enhanced fluorescence intensit...
We describe complexes of ruthenium and europium with rigid, 5'-6-locked 1,10-phenanthroline-containing nucleosides. Both nucleosides were synthesized from condensation of 5-amino-2'-deoxycytidine with the corresponding diketone. The ruthenium nucleoside displayed fluorescence characteristic of polypyridine ruthenium complexes with a maximum at 616 nm and a quantum yield of 0.011. Binding of eur...
A series of europium and terbium complexes based on a functionalized triazacyclononane carboxylate or phosphinate macrocyclic ligand is described. The influence of the anionic group, that is, carboxylate, methylphosphinate, or phenylphosphinate, on the photophysical properties was studied and rationalized on the basis of DFT calculated structures. The nature, number, and position of electron-do...
We report application of two-photon excitation of europium chelates to immunolabeling of epidermal growth factor receptor (EGFR) cell surface proteins on A431 cancer cells. The europium chelates are excited with two photons of infrared light and emit in the visible. Europium chelates are conjugated to antibodies for EGFR. A431 (human epidermoid carcinoma) cells are labeled with this conjugate a...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید