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Enhancement of europium emission band of europium tetracycline complex in the presence of cholesterol

SILVA, Flavia Rodrigues de Oliveira; SAMAD, Ricardo Elgul; GOMES, Laercio; COURROL, Lilia Coronato
Fonte: SPRINGER/PLENUM PUBLISHERS Publicador: SPRINGER/PLENUM PUBLISHERS
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
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We report here the observation, for the first time, of the enhancement of Europium-Tetracycline complex emission in cholesterol solutions. This enhancement was initially observed with the addition of the enzyme cholesterol oxidase, which produces H2O2, the agent driver of the Europium tetracycline complex, to the solution. However, it was found that the enzyme is not needed to enhance the luminescence. A calibration curve was determined, resulting in a simple method to measure the cholesterol quantity in a solution. This method shows that the complex can be used as a sensor to determine cholesterol in biological systems.

Europium luminescent polymeric microspheres fabricated by spray drying process

LUZ, Priscilla Paiva; PIRES, Ana Maria; SERRA, Osvaldo Antonio
Fonte: SPRINGER/PLENUM PUBLISHERS Publicador: SPRINGER/PLENUM PUBLISHERS
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
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The spray drying method was used to prepare luminescent microspheres. These microspheres were prepared by spraying an aqueous solution of dextrin and an europium(III) complex with subsequent drying in a hot medium. The spray dried powder was characterized by scanning electron microscopy (SEM) and photoluminescence spectroscopy (PL). Particle size distribution was estimated from SEM images. The ultrasonic spray drying technique was successfully applied to yield a microparticulated and red luminescent powder composed by the [Eu(dpa)(3)](3-) stop (dpa = dipicolinic acid) complex incorporated in dextrin microspheres.

Study of spectroscopic properties of Europium (III) Tris(beta-diketonate) complex and alpha-Cyclodextrin in aqueous medium

RIBEIRO, Anderson O.; SERRA, Osvaldo A.
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
ENG
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The solubilization of an europium (III) beta-diketonate chelate in aqueous medium and the changes in its photophysical properties upon its inclusion into an alpha-cyclodextrin hydrophobic cavity are described. The complex [Eu(tta)(3)center dot(H(2)O)(2)] (tta = 4,4,4-trifluoro-1-(thiophen-2-yl)butane-1,3-dione) was synthesized, characterized, and incorporated into the hydrophobic cavity by stirring in an alpha-cyclodextrin aqueous solution. The inclusion was confirmed by (1)H NMR, and the stoichiometry of association was obtained by the Job method. The maximum in the excitation spectrum of the alpha-CD inclusion compound in aqueous solution was shifted 28 nm compared with the maximum of non alpha-CD complex. The emission spectrum of the association is similar to that of the free solid complex and displays the characteristic (5)D(0) -> (7)F(0-4) Eu(3+) transitions.; FAPESP; CAPES; CNPq

Enhancement on the Europium emission band of Europium chlortetracycline complex in the presence of LDL

Teixeira, Luciane dos Santos; Grasso, Andrea Nastri; Monteiro, Andrea Moreira; Figueiredo Neto, Antonio Martins; Vieira Junior, Nilson Dias; Gidlund, Magnus Ake; Courrol, Lilia Coronato
Fonte: ACADEMIC PRESS INC ELSEVIER SCIENCE Publicador: ACADEMIC PRESS INC ELSEVIER SCIENCE
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
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Low-density lipoprotein (LDL) particles are the major cholesterol-carrying lipoprotein in the human circulation from the liver to peripheral tissues. High levels of LDL-Cholesterol (LDL-C) are known risk factor for the development of coronary artery disease (CAD). The most common approach to determine the LDLC in the clinical laboratory involves the Friedewald formula. However, in certain situations, this approach is inadequate. In this paper we report on the enhancement on the Europium emission band of Europium chlortetracycline complex (CTEu) in the presence of LDL. The emission intensity at 615 nm of the CTEu increases with increasing amounts of LDL. This phenomenon allowed us to propose a method to determine the LDL concentration in a sample composed by an aqueous solution of LDL. With this result we obtained LDL calibration curve, LOD (limit of detection) of 0.49 mg/mL and SD (standard deviation) of 0.003. We observed that CTEu complex provides a wider dynamic concentration-range for LDL determination than that from Eu-tetracycline previously. The averaged emission lifetimes of the CTEu and CTEu with LDL (1.5 mg/mL) complexes were measured as 15 and 46 Its, respectively. Study with some metallic interferents is presented. (C) 2010 Elsevier Inc. All rights reserved.; State of Sao Paulo Research Foundation (FAPESP); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); National institute of Science and Technology of Complex Fluids (INCT-FCx); National institute of Science and Technology of Complex Fluids (INCT-FCx); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); National Counsel of Technological and Scientific Development (CNPq)

Analytical quantification of low-density lipoprotein using europium tetracycline indicator

SILVA, Flavia Rodrigues De Oliveira; Monteiro, Andrea Moreira; Figueiredo Neto, Antonio Martins; Gidlund, Magnus Ake; Vieira Junior, Nilson Dias; COURROL, Lilia Coronato
Fonte: JOHN WILEY & SONS LTD Publicador: JOHN WILEY & SONS LTD
Tipo: Artigo de Revista Científica
ENG
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Low-density lipoprotein (LDL) is known as `bad` cholesterol. If too much LDL circulates in the blood it can be retained in the walls of the arteries, causing atherosclerosis. In this paper we showed an alternative method to quantify LDL using the europium tetracycline (EuTc) indicator. The optical properties of the EuTc complex were investigated in aqueous solutions containing LDL. An enhancement was observed of the europium luminescence in the solutions with LDL compared those without the lipoprotein. A method to quantify the amount of LDL in a sample, based on EuTc enhanced luminescence, is proposed. The enhancement mechanism is also discussed. Copyright (C) 2009 John Wiley & Sons, Ltd.; FAPESP; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); CNPq; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); IMFCx (Instituto do Milenio de Fluidos Complexos); IMFCx (Instituto do Milenio de Fluidos Complexos)

Investigation of the Europium Emission Spectra of the Europium-Oxytetracycline Complex in the Presence of Human Low-Density Lipoproteins

Teixeira, Luciane dos Santos; Grasso, Andrea Nastri; Monteiro, Andrea Moreira; Figueiredo Neto, Antonio Martins; Vieira Junior, Nilson Dias; Gidlund, Magnus Ake; Steffens, Juliana; Courrol, Lilia Coronato
Fonte: SPRINGER/PLENUM PUBLISHERS Publicador: SPRINGER/PLENUM PUBLISHERS
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
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Low-Density Lipoprotein (LDL), often known as ""bad cholesterol"" is one of the responsible to increase the risk of coronary arterial diseases. For this reason, the cholesterol present in the LDL particle has become one of the main parameters to be quantified in routine clinical diagnosis. A number of tools are available to assess LDL particles and estimate the cholesterol concentration in the blood. The most common methods to quantify the LDL in the plasma are the density gradient ultracentrifugation and nuclear magnetic resonance (NMR). However, these techniques require special equipments and can take a long time to provide the results. In this paper, we report on the increase of the Europium emission in Europium-oxytetracycline complex aqueous solutions in the presence of LDL. This increase is proportional to the LDL concentration in the solution. This phenomenum can be used to develop a method to quantify the number of LDL particles in a sample. A comparison between the performances of the oxytetracycline and the tetracycline in the complexes is also made.; CNPq; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); FAPESP; INCT-FCx (Instituto Nacional de Ciencias e Tecnologia de Fluidos Complexos); INCT-FCx (Instituto Nacional de Ciencias e Tecnologia de Fluidos Complexos)

Photophysical properties of a fluorene-bipyridine copolymer and its complexes with europium

Turchetti, D. A.; Rodrigues, P. C.; Berlim, L. S.; Zanlorenzi, C.; Faria, G. C.; Atvars, T. D. Z.; Schreiner, W. H.; Akcelrud, L. C.
Fonte: ELSEVIER SCIENCE SA; LAUSANNE Publicador: ELSEVIER SCIENCE SA; LAUSANNE
Tipo: Artigo de Revista Científica
ENG
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The synthesis and structural characterization of a europium complexed fluorene-bipyridine copolymer are described. A level of ion insertion of 80% in molar basis was achieved, and theoretical calculations showed that it required a twist of 179 degrees (49 kJ) between the pyridine units. Spectroscopy data showed that no electronic coupling between the main backbone and the complexation sites had occurred, but these hindered the interchain aggregation observed in the non complexed polymer. Preliminary electroluminescence studies showed that the EL and PL spectra are consistent, and that the ion had a trapping effect in the charge transport. (C) 2011 Elsevier B.V. All rights reserved.; INEO (National Institute for Organic Electronics); INEO (National Institute for Organic Electronics); CNPq (National Research Council); CNPq (National Research Council)

Synthesis, crystal structure and photoluminescence of a binuclear complex of europium(III) containing 3,5-dicarboxypyrazolate and succinate

Lahoud, Marcelo G.; Marques, Lippy F.; Silva, Patrícia B.; Jesus, Caio A. S.; Silva, Cecilia Carolina Pinheiro da; Ellena, Javier Alcides; Freitas, Rafael Sá de; Davolos, Marian R.; Frem, Regina C. G.
Fonte: Elsevier; Amsterdam Publicador: Elsevier; Amsterdam
Tipo: Artigo de Revista Científica
ENG
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The new europium binuclear complex [Eu2(dcpz)2(suc)(H2O)8] (H2O)1.5 (dcpz = 3,5-dicarboxypyrazolate and suc = succinate) has been synthesized and structurally characterized by single crystal X-ray diffraction methods. The binuclear complex crystallizes in the triclinic space group P 1 and consists of two lanthanide ions linked by two different bridging organic ligands. 3D supramolecular framework is constructed by hydrogen bonds. The compound shows strong red emission under UV excitation at room temperature associated to IL transitions indicating a ligand to metal energy transfer mechanism since the triplet energy level lies higher than that of europium 5D0 level. Magnetic susceptibility studies showed weak temperature dependence characteristic of the Van Vleck paramagnetism.; CNPq; CAPES; FAPESP

Desenvolvimento de um biossensor de peróxido de hidrogênio de baixo custo baseado na emissão do európio III.; Development of a low cost hydrogen peroxide biosensor based on europium (III).

Silva, Flávia Rodrigues de Oliveira
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 12/03/2008 PT
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Neste trabalho estudou-se as propriedades ópticas do complexo Európio- Tetraciclina (EuTc), determinando as melhores condições para se obter uma formação eficiente do complexo. Parâmetros ópticos como absorção, emissão, tempo de vida e índice de refração foram obtidos. Variação da concentração de európio no complexo, da temperatura, pH ótimo e tempo de reação das soluções foram analisados. Um aumento na banda de emissão do európio foi observado com adição de peróxido de hidrogênio (HP) na solução. As amostras foram preparadas com pH neutro e a luminescência visível do lantanídeo foi detectada após uma incubação das amostras por 30 min. Um método direto para determinação de peróxido de uréia (PHU) e colesterol, em solução, usando a fluorescência do complexo EuTc é descrito. Os resultados mostram que o complexo é ainda mais sensível para o peróxido de uréia, aumentando a intensidade de emissão em até 40 vezes, do que para o peróxido de hidrogênio, que proporciona um aumento máximo de 15 vezes, quando comparados ao EuTc puro. É reportado também, pela primeira vez, que para a determinação do colesterol total, utilizando-se a sonda EuTc, não há necessidade de adição de enzima na solução...

Estudos  espectroscópicos  dos complexos európio-tetraciclinas e suas aplicações na detecção de peróxido de hidrogênio e peróxido de uréia; Spectroscopic studies of europium-tetracyclines complexes and their applications in detection of hydrogen peroxide and urea peroxide

Grasso, Andrea Nastri
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 24/06/2010 PT
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Neste trabalho foram estudadas as propriedades espectroscópicas do íon európio trivalente complexado à componentes da família das tetraciclinas, a clorotetraciclina, oxitetraciclina e metaciclina, em presença de peróxido de hidrogênio e peróxido de uréia. Para isso foram obtidos os parâmetros ópticos de absorção, emissão, tempo de vida e construídas curvas de calibração para os espectros de luminescência. Realizaram-se experimentos com compostos inorgânicos juntamente com os complexos a fim de verificar a interferência dos mesmos. Também foram realizados estudos para determinação de glicose utilizando os complexos európiotetraciclinas como biossensor. Os resultados mostram que os complexos európiotetraciclinas apresentam um espectro de emissão bem definido na região do visível e, na presença de peróxido de hidrogênio ou peróxido de uréia, há um aumento sensível na luminescência e tempo de decaimento. Assim, os complexos európiotetraciclinas estudados podem ser utilizados como biossensores para determinação dos peróxidos de hidrogênio e uréia, sendo um método realizado em temperatura ambiente, direto e de baixo custo. Um método indireto para determinação de glicose foi estudado através da adição da enzima glicose oxidase aos complexos európiotetraciclinas na presença de glicose no qual há como produto o peróxido de hidrogênio.; In this work were studied the spectroscopic properties of trivalent europium ion complexed with components of tetracycline family...

Estudos das propriedades ópticas dos complexos európio tetraciclinas e suas aplicações na detecção de lipoproteínas; Studies of optical properties of complexes europium tetracycline and its applications in detection of lipoproteins

Teixeira, Luciane dos Santos
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 26/07/2010 PT
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Este trabalho apresenta as propriedades ópticas dos complexos Európio Tetraciclinas (EuTcs) na presença de LDL e de LDL oxidada com potenciais aplicações em análises clínicas. Foram escolhidos quatro elementos da família das Tetraciclinas: Tetraciclina (Tc), Clorotetraciclina (CTc), Metatetraciclina (MTc) e Oxitetraciclina (OTc) para fazerem parte dos complexos com o íon európio. As melhores condições para se formar os complexos eficientemente foram determinadas, através das medidas dos parâmetros ópticos como: absorção, emissão e de tempo de vida. As melhores concentrações de európio nos complexos EuTcs e possíveis influências de íons inorgânicos normalmente presentes no plasma sanguíneo também foram analisadas. As amostras foram preparadas em pH neutro e a luminescência visível do lantanídeo foi detectada após tempo de repouso das amostras de 15 minutos. Os resultados deste trabalho mostraram que as moléculas de LDL e de LDL oxidada apresentaram um importante papel no aumento da intensidade de emissão dos complexos das Tcs. As medidas realizadas com os complexos EuTcs não apresentaram deslocamentos nos comprimentos de onda dos espectros de absorção e de emissão na presença de LDL, o que demonstra a ausência de interação direta entre as moléculas de Tcs e as moléculas de LDL e LDL oxidada. No entanto...

Orientação óptica de spin em semicondutores magnéticos - calcógenos de európio; Spin optical orientation in magnetic semiconductors-europium chalcogenides.

Galgano, Giovanni Decot
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 19/06/2012 PT
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A investigação das propriedades ópticas e sua relação com as propriedades magnéticas dos semicondutores é de grande interesse para a comunidade científica, em virtude da enorme demanda por novas tecnologias e funcionalidades que podem surgir dessas pesquisas. Os calcógenos de európio são semicondutores intrinsecamente magnéticos, transparentes na região visível do espectro eletromagnético e integráveis em matrizes de silício e nitreto de gálio, sendo assim fortes candidatos a aplicações tecnológicas envolvendo magnetismo e óptica. Neste trabalho são investigados os espectros de absorção e fotoluminescência dos calcógenos de európio, com base no modelo 4f -> 5d('t IND. 2g') da transição óptica de dipolo elétrico, o qual mostrou-se totalmente adequado para a descrição da absorção óptica nos calcógenos de európio em função do campo magnético aplicado, explicando a presença de linhas de absorção estreitas e dicróicas nos espectros em campo alto e a forma larga dos espectros de absorção em campo nulo. Nos espectros de fotoluminescência do EuTe, entretanto, foram detectados estados eletrônicos não contemplados pelo modelo 4f -> 5d('t IND. 2g') , em especial uma banda de emissão denominada 'MX IND. 0'...

Preparation, characterization and spectroscopy of the europium diphenylphosphinate complex

Stucchi, Elizabeth B.; Scarpari, Sérgio L.; Couto Dos Santos, Marcos A.; Leite, Sérgio R. A.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 89-92
ENG
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The purpose of this work is to study the preparation and spectroscopic behavior of the europium diphenylphosphinate complex -Eu(DPP)3. Elemental and thermogravimetric analysis, powder X-ray diffractometry, and infrared spectroscopy were applied to characterize the formula of the final product and the sixfold coordination of the Eu3+ ion. Excitation and emission spectra have been recorded at liquid nitrogen and room temperatures. The 5D0→7F2 transition intensity decreases when T decreases in comparison to the 5D0→7F1 transition intensity. Molecular mechanic calculations were developed in order to obtain the spatial coordinates of the Eu3+ and ligand ions. The simple overlap model was used to calculate the total splitting of the 5D0→7F1 transition, 5D0→7F0/5D 0→7F2 ntensity ratio and the intensity parameters, Ωλ (λ=2 and 4). Good agreements between theoretical predictions and experimental results have been obtained with g=2/3 as the effective charge and α=0.8×10-24 cm3 as the isotropic polarizability of the oxygen. © 1998 Elsevier Science S.A.

Strongly luminescent, highly ionic europium in a lanthanum diphenylphosphinate matrix

Abreu, Edson M.; Francisco, Cristina S.; Klein, Stanlei I.; Stucchi, Elizabeth B.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 332-337
ENG
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A series of insoluble, chemically inert and thermally stable compounds La1-xEux(DPP)3 (x = 0.50, 0.20, 0.10, and 0.050; DPP = diphenylphosphinate) was synthesized and characterized by elemental and thermogravimetric analysis, FT Infrared spectroscopy and X-ray powder diffraction. Luminescence spectroscopy at both 77 and 298 K showed changes in the intensity of the hypersensitive transition 5D 0 → 7F2 of Eu3+ which are dependent of the excitation wavelength, suggesting that the europium occupies two different sites in the compounds. The large quantum efficiency and quantum yield, as well as the long radiative lifetime of the 5D0 Eu3+ level of the series of compounds, which are desirable qualities for light-conversion molecular devices, are discussed in terms of the interactions and the energy transfer process between the ligands and the metal ion. © 2012 Elsevier B.V. All rights reserved.

Synthesis, crystal structure and photoluminescence of a binuclear complex of europium(III) containing 3,5-dicarboxypyrazolate and succinate

Lahoud, Marcelo G.; Marques, Lippy F.; Da Silva, Patrícia B.; De Jesus, Caio A.S.; Da Silva, Cecilia C.P.; Ellena, Javier; Freitas, Rafael S.; Davolos, Marian R.; Frem, Regina C.G.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 1-7
ENG
Relevância na Pesquisa
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The new europium binuclear complex [Eu2(dcpz) 2(suc)(H2O)8]·(H2O) 1.5 (dcpz = 3,5-dicarboxypyrazolate and suc = succinate) has been synthesized and structurally characterized by single crystal X-ray diffraction methods. The binuclear complex crystallizes in the triclinic space group P1̄ and consists of two lanthanide ions linked by two different bridging organic ligands. 3D supramolecular framework is constructed by hydrogen bonds. The compound shows strong red emission under UV excitation at room temperature associated to IL transitions indicating a ligand to metal energy transfer mechanism since the triplet energy level lies higher than that of europium 5D0 level. Magnetic susceptibility studies showed weak temperature dependence characteristic of the Van Vleck paramagnetism. © 2013 Elsevier Ltd. All rights reserved.

Optical characterization of europium-doped indium hydroxide nanocubes obtained by Microwave-Assisted Hydrothermal method

Motta, Fabiana Villela Da; Marques, Ana Paula De Azevedo; Araújo, Vinícius Dantas De; Tavares, Mara Tatiane De Souza; Delmonte, Mauricio Roberto Bomio; Paskocimas, Carlos Alberto; Li, Máximo Siu; Nascimento, Rubens Maribondo Do; Longo, Elson
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: 0-0
ENG
Relevância na Pesquisa
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Crystalline europium-doped indium hydroxide (In(OH)3:Eu) nanostructures were prepared by rapid and efficient Microwave-Assisted Hydrothermal (MAH) method. Nanostructures were obtained at low temperature. FE-SEM images confirm that these samples are composed of 3D nanostructures. XRD, optical diffuse reflectance and photoluminescence (PL) measurements were used to characterize the products. Emission spectra of europium-doped indium hydroxide (IH:xEu) samples under excitation (350.7 nm) presented broad band emission regarding the indium hydroxide (IH) matrix and 5D0 → 7F0, 5D0 → 7F1, 5D0 → 7F2, 5D0 → 7F3 and 5D0 → 7F4 europium transitions at 582, 596, 618, 653 and 701 nm, respectively. Relative intensities of Eu3+ emissions increased as the concentration of this ion increased from 0, 1, 2, 4 and 8 mol %, of Eu3+, but the luminescence is drastically quenched for the IH matrix.

Optical characterization of europium-doped indium hydroxide nanocubes obtained by Microwave-Assisted Hydrothermal method

Motta, Fabiana Villela Da; Marques, Ana Paula De Azevedo; Araújo, Vinícius Dantas De; Tavares, Mara Tatiane De Souza; Delmonte, Mauricio Roberto Bomio; Paskocimas, Carlos Alberto; Li, Máximo Siu; Nascimento, Rubens Maribondo Do; Longo, Elson
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: 933-939
ENG
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Crystalline europium-doped indium hydroxide (In(OH)3:Eu) nanostructures were prepared by rapid and efficient Microwave-Assisted Hydrothermal (MAH) method. Nanostructures were obtained at low temperature. FE-SEM images confirm that these samples are composed of 3D nanostructures. XRD, optical diffuse reflectance and photoluminescence (PL) measurements were used to characterize the products. Emission spectra of europium-doped indium hydroxide (IH:xEu) samples under excitation (350.7 nm) presented broad band emission regarding the indium hydroxide (IH) matrix and 5D0 → 7F0, 5D0 → 7F1, 5D0 → 7F2, 5D0 → 7F3 and 5D0 → 7F4 europium transitions at 582, 596, 618, 653 and 701 nm, respectively. Relative intensities of Eu3+ emissions increased as the concentration of this ion increased from 0, 1, 2, 4 and 8 mol %, of Eu3+, but the luminescence is drastically quenched for the IH matrix.

Incorporation of europium III complex into nanoparticles and films obtained by the Sol-Gel methodology

Sousa,Faley Jean de; Lima,Gilberto Pansani Altino de; Ávila,Lílian Rodrigues; Ciuffi,Katia Jorge; Calefi,Paulo Sergio; Nassar,Eduardo José
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2010 EN
Relevância na Pesquisa
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The sol-gel process is very effective for the preparation of new materials with potential applications in optics, sensors, catalyst supports, coatings, and specialty inorganic polymers that can be used as hosts for the accommodation of organic molecules. The low temperature employed in the process is the main advantage of this methodology. In this work, the europium (III) complex with 1,10-phenantroline was prepared, and this luminescent complex was incorporated into silica nanoparticles and films by the sol-gel process. The nanoparticles were obtained by the modified Stöber methodology. The films were obtained by the dip-coating technique, at different deposition rates and numbers of layers. The nanoparticles and films were characterized by photoluminescence, thermal analysis, and Raman and infrared spectroscopies. Characterization revealed that the europium (III) complex was not affected upon incorporation into the nanoparticles and films, opening a new field for the application of these materials.

Optical characterization of europium-doped indium hydroxide nanocubes obtained by Microwave-Assisted Hydrothermal method

Motta,Fabiana Villela da; Marques,Ana Paula de Azevedo; Araújo,Vinícius Dantas de; Tavares,Mara Tatiane de Souza; Delmonte,Mauricio Roberto Bomio; Paskocimas,Carlos Alberto; Li,Máximo Siu; Nascimento,Rubens Maribondo do; Longo,Elson
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2014 EN
Relevância na Pesquisa
37.35195%
Crystalline europium-doped indium hydroxide (In(OH)3:Eu) nanostructures were prepared by rapid and efficient Microwave-Assisted Hydrothermal (MAH) method. Nanostructures were obtained at low temperature. FE-SEM images confirm that these samples are composed of 3D nanostructures. XRD, optical diffuse reflectance and photoluminescence (PL) measurements were used to characterize the products. Emission spectra of europium-doped indium hydroxide (IH:xEu) samples under excitation (350.7 nm) presented broad band emission regarding the indium hydroxide (IH) matrix and 5D0 → 7F0, 5D0 → 7F1, 5D0 → 7F2, 5D0 → 7F3 and 5D0 → 7F4 europium transitions at 582, 596, 618, 653 and 701 nm, respectively. Relative intensities of Eu3+ emissions increased as the concentration of this ion increased from 0, 1, 2, 4 and 8 mol %, of Eu3+, but the luminescence is drastically quenched for the IH matrix.

Optical characterization of europium-doped indium hydroxide nanocubes obtained by Microwave-Assisted Hydrothermal method

Motta, Fabiana Villela Da; Marques, Ana Paula De Azevedo; Araújo, Vinícius Dantas De; Tavares, Mara Tatiane De Souza; Delmonte, Mauricio Roberto Bomio; Paskocimas, Carlos Alberto; Li, Máximo Siu; Nascimento, Rubens Maribondo Do; Longo, Elson
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: 933-939
ENG
Relevância na Pesquisa
37.35195%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Crystalline europium-doped indium hydroxide (In(OH)3:Eu) nanostructures were prepared by rapid and efficient Microwave-Assisted Hydrothermal (MAH) method. Nanostructures were obtained at low temperature. FE-SEM images confirm that these samples are composed of 3D nanostructures. XRD, optical diffuse reflectance and photoluminescence (PL) measurements were used to characterize the products. Emission spectra of europium-doped indium hydroxide (IH:xEu) samples under excitation (350.7 nm) presented broad band emission regarding the indium hydroxide (IH) matrix and 5D0 → 7F0, 5D0 → 7F1, 5D0 → 7F2, 5D0 → 7F3 and 5D0 → 7F4 europium transitions at 582, 596, 618, 653 and 701 nm, respectively. Relative intensities of Eu3+ emissions increased as the concentration of this ion increased from 0, 1, 2, 4 and 8 mol %, of Eu3+, but the luminescence is drastically quenched for the IH matrix.