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1.
Dalton Trans ; 51(14): 5426-5433, 2022 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-35311836

RESUMO

Temperature sensing plays essential roles in both fundamental research and high-tech applications. In this work, three isomorphic hexanuclear lanthanide metal-organic frameworks (Ln-MOFs), Ln(BPDC-xN) (Ln = Eu3+/Tb3+, x = 0, 1, 2) were prepared based on the cluster-based synthesis strategy with three structurally similar dicarboxylate ligands 4,4'-biphenyldicarboxylic acid (H2BPDC-0N), 6-(4-carboxyphenyl)nicotinic acid (H2BPDC-1N), and [2,2'-bipyridine]-5,5'-dicarboxylic acid (H2BPDC-2N) as the organic linkers. The as-synthesized Ln-MOFs were fully characterized using single-crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), elemental analysis (EA), and Fourier transform infrared spectra (FT-IR). Using a Eu3+/Tb3+ co-doping approach, Eu0.001Tb0.999(BPDC-xN) (x = 0, 1, 2) were identified as potential ratiometric luminescence thermometers. Since there are two suitable distances between the energy donors and acceptors within the framework for efficient energy transfer, all Eu0.001Tb0.999(BPDC-xN) (x = 0, 1, 2) maintain high relative sensitivity over a wide temperature range from 50 K to 300 K.

2.
ACS Biomater Sci Eng ; 7(10): 4999-5006, 2021 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-34550683

RESUMO

Iron-based metal-organic frameworks (MOFs) have been reported to have great potential for encapsulating doxorubicin hydrochloride (DOX), which is a frequently used anthracycline anticancer drug. However, developing a facile approach to realize high loading capacity and efficiency as well as controlled release of DOX in MOFs remains a huge challenge. Herein, we synthesized water-stable MIL-101(Fe)-C4H4 through a microwave-assisted method. It was found the nano-MOFs acted as nanosponges when soaked in a DOX alkaline aqueous solution with a loading capacity experimentally up to 24.5 wt %, while maintaininga loading efficiency as high as 98%. The mechanism of the interaction between DOX and nanoMOFs was investigated by absorption spectra and density functional theory (DFT) calculations, which revealed that the deprotonated DOX was electrostatically adsorbed to the unsaturated Fe3OCl(COO)6·H2O (named Fe3 trimers). In addition, the as-designed poly(ethylene glycol-co-propylene glycol) (F127) modified nanoparticles (F127-DOX-MIL) could be decomposed under the stimulation of glutathione (GSH) and ATP. As a result, DOX and Fe(III) ions were released, and they could undergo a Fenton-like reaction with the endogenous H2O2 to generate the highly toxic hydroxyl radical (·OH). The in vitro experiments indicated that F127-DOX-MIL could cause remarkable Hela cells inhibition through chemotherapy and chemodynamic therapy. Our study provides a new strategy to design a GSH/ATP-responsive drug-delivery nanosystem for chemo/chemodynamic therapy.


Assuntos
Doxorrubicina , Estruturas Metalorgânicas , Compostos Férricos , Células HeLa , Humanos , Peróxido de Hidrogênio
3.
Chem Commun (Camb) ; 56(74): 10851-10854, 2020 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-32812958

RESUMO

A series of isostructural Ln-MOFs, namely Eu(BPDC-xN)(x = 0, 1, 2), with different numbers of nitrogen atoms were designed and synthesized. Due to the strong affinity between the bare phosphate group of NADPH and nitrogen functional sites, the highly selective and sensitive detection of NADPH was realized. Furthermore, as the number of sites was increased, the sensitivity significantly increased, with a detection limit as low as 0.43 µM.

4.
Dalton Trans ; 47(29): 9717-9723, 2018 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-29978877

RESUMO

Bi can exist in a variety of chemical states (with varying ionic charges) and the microstructure of the glass surrounding the ions can be engineered to manipulate the chemical state. In this work, efficient enhancement of Ho3+ emission is observed with the change in local glass environment around Bi by adding Al2O3 to multi-component germanosilicate glass. In this multi-component glass, Al3+ can form tetrahedral AlO4 by accepting the non-bridging oxygen (NBO) and then, the addition of the AlO4-tetrahedron to the glass network facilitates the diffusion of alkali metals. Hence, Al2O3 decreases the Ba2+-rich domain and is conducive to the existence of Bi ions that are at low valence state. Moreover, the emission spectra indicate high efficiency energy transfer (ET) derived from NIR emission centers (Bi0/Bi+) located in close proximity to the Ho3+ ions. These results indicate that the optimized fluorescence of Ho3+ for optical fiber laser can be achieved by adjusting the local structure of the host glass.

5.
Opt Lett ; 43(14): 3281-3284, 2018 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-30004486

RESUMO

Higher concentrations of rare earth (RE) ions in glass materials would be favorable for the output of single-frequency fiber lasers. In this Letter, we adjusted the topological structure of glass networks through controlling the numbers of non-bridging oxygens (NBOs) and bridging oxygens (BOs) by tuning the composition of the glasses, hence increasing the RE doping concentration of germanosilicate glasses. The increased flexibility of the glass networks favors the distribution of clusters of RE ions to decrease fluorescence quenching, which was validated by both our experimental and theoretical results. To the best of our knowledge, for the first time, a highly Er3+-doped (up to 7 mol. %) heavy metal oxide glass was fabricated without quenching by tuning the components of the glass. In addition, we have demonstrated an approach to enhance the fluorescence properties of heavily RE-doped glass materials by tailoring network topology.

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