Supported core-shell nanobiosensors for quantitative fluorescence imaging of extracellular pH

Covalent “click” cycloaddition was used to functionalize silica substrates with pH-sensitive nanoparticles, thus producing uniform and highly luminescent analytical devices usable in both commercial fluorimeters and fluorescence microscopes. Quantitative and spatially-resolved extracellular pH measurements were successfully achieved on live cardiac fibroblasts with these novel ion-sensitive surfaces.

Preparo e caracterização de compósitos polímero/cerâmica com potencial aplicação como sensor multifuncional

Pós-graduação em Química - IQ

Complexos heterobilantanídicos luminescentes sob excitação UV e raios X

Pós-graduação em Química - IQ

Deposição de filmes finos de SnO2 e GaAs, visando confecção de dispositivos baseados na heterojunção SnO2/GaAs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo de nanocompósitos luminescentes baseados em complexos de Eu(III) e Ir(III) ancorados à nanopartículas de sílica por bases de Schiff

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Luminescence of Eu3+ in the thin film heterojunction GaAs/SnO2

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Luminescence properties of Eu-complex formations into ordered mesoporous silica particles obtained by the spray pyrolysis process

Ordered mesoporous, highly luminescent SiO2 particles have been synthesized by spray pyrolysis from solutions containing tetraethylorthosilicate (TEOS), Eu(NO3)3.6H2O, and cetyltrimethylammonium bromide (CTAB) as structure-directing agents. The 1,10-phenantroline (Phen) molecules were coordinated in a post-synthesis step by a simple wet impregnation method. In addition, other matrices were also prepared by the encapsulation of europium complex Eu(fod)3 (where fod = 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionato) into mesoporous silica, and then the Phen molecules were encapsulated by different impregnation steps, after which the luminescence properties were investigated. The obtained materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder x-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Powders with polydisperse spherical grains were obtained, displaying an ordered hexagonal array of mesochannels. Luminescence results revealed that Phen molecules had been successfully coordinated as an additional ligand in the Eu(fod)3 complex into the channels of the mesoporous particles without disrupting the structure.

Estudo do efeito de cério como sensibilizador e ativador, em matrizes de difenilfosfinatos de lantânio, dopadas com európio e/ou térbio

This paper aims the preparation, characterization and study of luminescence, particularly as for the cerium ion action as activator or sensitizer, in diphenylphosphinate of lanthanum compounds trivalent ions cerium-, europium-, and/or terbium-doped. The following compounds were prepared and studied: i) La1-(x+y)CexEuy(DFF)3; ii) La1-(x+y)CexTby(DFF)3; iii) La1-(x+y+z)CexEuyTbz(DFF)3, with x = 10%, y = 5% e z = 5%. The diphenylphosphinate of lanthanum, Ln[(Ph2)PO2]3, are complexes obtained by the mixture of lanthanides chlorides with diphenylphosphinic acid, ethanol medium. These compounds make white powders, crystalline, insoluble in normal temperature and pressure, and are chemically and thermally stable. When doping with Ce3+, Eu3+ and/or Tb3+, the compounds present characteristic luminescence. Luminescent materials are made of a host matrix incorporated with few amounts of ions called activators, which are able to present luminescence after being excited by UV light or high energy radiation, and sensitizer ions, which have the role of absorbing excitation energy and transfer it to the activator, for it to emit luminescence radiation. The infrared vibrational spectroscopy indicates that the coordination occurs by the oxygens of phosphorile group with ΔνPO of about 40 cm-1 compared to the free ligand. The X Ray difractograms of compounds Eu- and/or Tb-doped are similar, but they present profile of diffraction different observed by Stucchi and col. In previous papers, indicated an influence of Ce in the crystalline phase formation of these matrices. In luminescence spectrums, the excitation that can be made by the levels of ligand in 273 nm, or cerium ion in area between 300 and 400 nm were observed. In the emission spectrum, with excitation in 273 nm, is possible to observe the emission of Ce3+ below 400 nm and the Eu3+ in 592, 611 and 617 nm, and the...as a sensitizer to.

Preparação e caracterização de novos híbridos orgânicos-inorgânicos baseados em carboximetilcelulose/polifosfato de sódio dopados com 'Eu'Cl IND.3

Organic- inorganic hybrid (HOI) are materials prepared with the combination of inorganic and organic components. The properties of a hybrid material are unique, not being the sum of each individual component added. This occurs because there is a synergism that depends of the chemical nature of organic and inorganic components, of the size and morphology of their domains. The sodium carboxymethylcellulose (CMC) it's an anionic polymer obtained of the cellulose, very soluble in water in which forms both solutions themselves and gels. The sodium polyphosphate (NaPO3)n, known commercially as Graham Salt is the only polyphosphate soluble in water, and it's the polyphosphate with the longest chain. At the present work it was prepared and characterized new phosphate organic- inorganic hybrids films of carboxymethylcellulose / sodium phosphate and luminescent films of CMC/NaPO3 doped with europium chloride (EuCl3). The films where prepared in several proportions. At first, it was set the amount of water to be used and the amount of carboxymethylcellulose, changing the concentrations of sodium polyphosphate and europium chloride. After pre-establishing concentrations, for each film, the components were submitted to constant agitation and subsequent drying. The inorganic-organic hybrid films were characterized by, TG, DR-X, DMA, FT-IR, UV-Vis-NIR, RMN 31P e 13C and at last, a study of luminescence was made. The hybrid films obtained are transparent and macroscopically homogeneous, however, the MET measures showed the formation of micro-islands of polyphosphate along the material, this fact indicates a bigger fragmentation of the films and this is verified by DMA analysis which shows a smaller resistance of the film with the increase of the concentration of phosphate. Both spectrum FT-IR and RMN analysis of the films, don't show the formation of new bands of their precursors, CMC e NaPO3,....

Surface modified Mg-doped ZnO QDs for biological imaging

Fundação Amparo à Pesquisa Estado de São Paulo (FAPESP)

Effect of silica surface on luminescence properties of tb3+-glutamic acid.

We studied the effect of silica surface on luminescence properties of terbium complex by spectroscopy characterization, where microparticles of mesoporous silica type MSU-X was prepared. We used silica with different surface: calcined, washed, functionalized with 3- aminopropyl-triethoxysilane (APTES), and 3-glycidoxypropyl-trimethoxysilane (GPTMS); impregnated with Tb3+-glutamic acid complex. The obtained materials were characterized by scanning electron microscopy, porosity measurements, small-angle X-ray scattering, as structural characterization; Fourier transform infrared and luminescence spectroscopy, as spectroscopy characterization. Finally, we observed that functional groups at the silica surface lead to changes on luminescent properties of the final materials. The observed shift of the absorption and emission bands can be assigned to the effect of the functional groups of mesoporous silica.

Íons terras raras inseridos em matrizes poliméricas de germânio e enxofre para preparação de materiais com propriedades ópticas

Pós-graduação em Química - IQ

Estudo da ação de derivados semi-sintéticos de curcumina em linhagens celulares de câncer humano

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Metalosupramoléculas discretas e Metal Organic Frameworks (MOFs) baseados em íons lantanídeos: design, síntese, caracterização e propriedades

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Propriedades luminescentes de polioxometalato contendo európio(III) correlacionadas à sua conformação em sólido estendido e em filmes auto-organizados de Langmuir e Langmuir-Blodgett

Pós-graduação em Química - IQ