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1.
Small molecular biothiols, cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), play important roles in organisms, and their concentration levels are indicative of some human diseases. Herein we report an organic dye-conjugated β-diketonate-Eu3+ complex, [Eu(NBD-keto)3(DPBT)] (NBD-keto: 7-nitro-2,1,3-benzoxadiazole (NBD)-conjugated to 1,1,1,2,2-pentafluoro-5-phenyl-3,5-pentanedionate through a “O” ether bond; DPBT: 2-(N,N-diethylanilin-4-yl)-4,6-bis(3,5-dimethylpyrazol-1-yl)-1,3,5-triazine), which acts as a unique luminescent probe for detecting and discriminating biothiols. [Eu(NBD-keto)3(DPBT)] itself is not luminescent due to intramolecular interactions between NBD and β-diketonate-Eu3+ moieties. Upon reaction with biothiols, the β-diketonate-Eu3+ complex [Eu(keto)3(DPBT)] is generated, which emits long-lived red emission at 610 nm. Meanwhile, three biothiol-substituted NBD derivatives that exhibit different luminescence behaviors, green emissive (short-lived) NBD-NR (R=Cys or Hcy) at 540 nm and non-luminescent NBD-SR (R=GSH), are also generated. These luminescence response behaviors allow time-gated and steady-state luminescence modes to be combined for detecting total biothiols and discriminating GSH and Cys/Hcy. Using this probe, the quantitative detection and discrimination of GSH and Cys/Hcy in lysis solutions of HeLa cells were realized, which revealed the potential of the probe for biomedical applications. 相似文献
2.
Equilibria of EuO dissolution and dissociation in molten (NaBr + NaI) mixtures of 0.77:0.23 and 0.31:0.69 compositions at T = 973 K were studied by potentiometric titration method using Pt(O2)|ZrO2(Y2O3) indicator electrode. The solubility product indices of EuO are (7.81 ± 0.08) and (8.43 ± 0.16) in the melts of 0.77:0.23 and 0.31:0.69 compositions. The corresponding dissociation constant indices are (4.96 ± 0.04) and (5.54 ± 0.06), respectively (all the parameters are in molality). Non-dissociated EuO is the prevailing form in all the saturated solutions of europium monoxide. The decrease of the iodide ion concentration in the melts results in strengthening of EuO dissociation that is explained by introduction of harder Pearson’s base (Br−) in sodium iodide melt. In its turn this increases the fixation degree of Eu2+ in mixed halide complexes. The total solubility of EuO decreases going from NaI melt to the (bromide + iodide) mixtures that is caused by the decrease of ‘physical’ solubility of non-dissociated oxide which occupies hollow spaces of enough large size in the ionic solvents. The quantity of these hollow spaces diminishes at the sequential Br− → I− substitution. 相似文献
3.
David M. Rackham 《光谱学快报》2013,46(8):517-520
Paper 16 in this series1, 2, 3 was concerned with the equilibrium binding constants (K) of the shift reagent Europium tris (2, 2, 6, 6-tetramethylheptane-3, 5-dionate), Eu(thd)3, with primary, secondary and tertiary amines. One nitrogen heterocycle, pyridine, and two of its derivatives (see Table) were included. In the present paper we describe the binding constants for a further 9 nitrogen containing heterocycles and relate these to basicity and steric effects. 相似文献
4.
5.
Yoshitaka Misawa 《Journal of solid state chemistry》2011,184(6):1478-1483
Structures and magnetic properties of double perovskite-type oxides Eu2LnTaO6 (Ln=Eu, Dy-Lu) were investigated. These compounds adopt a distorted double perovskite structure with space group P21/n. Magnetic susceptibility, specific heat, and 151Eu Mössbauer spectrum measurements show that the Eu2+ ions at the 12-coordinate sites of the perovskite structure are antiferromagnetically ordered at ∼4 K, and that Ln3+ ions at the 6-coordinate site are in the paramagnetic state down to 1.8 K. 相似文献
6.
7.
A comparative study of the luminescent properties of Y2O3:Eu3+ phosphor powders and thin films sputtered from targets prepared from combustion synthesized powders is reported. Thin films of (Y0.96Eu0.04)2O3 were deposited on silicon substrates. Films deposited at 600 °C had both monoclinic and cubic phases of Y2O3, which developed to an oriented cubic phase after annealing. Films and powders showed a linear dependence of the intensity of the 5D7→7F2 (611 nm) transition with temperature in the range 26-660 °C with an average rate of change of 1.8×10−4 °C−1. The rate of change appears to be dependent on the Eu3+ concentration. This work shows that these thin films can be used as thermographic phosphors for remote temperature measurements. 相似文献
8.
Craig P. Montgomery Elizabeth J. New Lars O. Palsson David Parker Andrei S. Batsanov Laurent Lamarque 《Helvetica chimica acta》2009,92(11):2186-2213
A series of seven emissive europium(III) and terbium(III) complexes was prepared, incorporating a 3‐pyridyl‐4‐azaxanthone or 3‐pyrazolyl‐4‐azaxanthone sensitising moiety within a polydentate macrocyclic ligand. High overall emission quantum yields in aqueous media are attenuated in the presence of protein or certain oxy anions due to displacement of the N,N′‐chelated sensitiser. Nevertheless, these complexes are taken into cells and tend to localise over the first few hours in mitochondria before being trafficked to endosomal compartments. Cell uptake studies, in the presence of competitive inhibitors or promoters of well‐defined uptake pathways, reveal a common uptake mechanism involving macropinocytosis. 相似文献
9.
C. Leroy T. Cardinal M. Treguer-Delapierre C. Boissière C. Sanchez F. Pellé 《Journal of luminescence》2009,129(12):1641-1645
In this paper, a series of europium-activated titania mesoporous and dense thin films were prepared by sol-gel process. Structural characterizations show that high europium ion loadings can be incorporated into titanium dioxide walls without destroying the mesoporous arrangement. However, high europium content locks the titanium dioxide crystallization process. Upon 10% europium ions loading, mesoporous thin films are mainly amorphous, whereas dense ones are still partially crystallized. Eu3+ ion luminescence has been investigated by exciting through the semiconductor host lattice. Emission features reveal that europium ions adopt similar environments (nanocrystalline and glassy-like ones) in both dense and mesoporous thin films. Fluctuations of europium emission under continuous UV excitation have been observed. One observes that the effect strongly depends on the thin films’ crystalline character which is strongly related with the texturation and existence at the mesoscopic length scale. 相似文献
10.