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Silva AMB, Jesus LS, Correa W, Junot DO, Caldas LVE, Dantas NO, Souza DN, Silva ACA. Luminescence characterization of BioGlass undoped and doped with europium and silver ions. Appl Radiat Isot 2023; 201:110997. [PMID: 37666051 DOI: 10.1016/j.apradiso.2023.110997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/27/2023] [Accepted: 08/22/2023] [Indexed: 09/06/2023]
Abstract
The objective of this study was to investigate the properties of BioGlass, with and without doping with europium and silver, with a specific focus on its potential application in thermoluminescent (TL) and optically stimulated luminescent (OSL) dosimetry. The structural and optical characteristics of the samples were also analyzed using techniques such as X-ray diffraction (XRD), optical absorption (OA), and fluorescence spectroscopy (FL). An XRD analysis confirmed the amorphous phase of the BioGlass. OA and FL spectra were obtained at room temperature, and characteristic bands of dopant ions were observed which confirmed the incorporation of the Eu3+ ions and silver nanoparticles Ag(NP) ion into the BioGlass. The OSL decay curves exhibited a characteristic exponential behavior, with a notable presence of fast and medium decay components; this suggests that the charge traps within the BioGlass samples possess a high photoionization cross section when exposed to blue LEDs, which are commonly used as the light source in OSL readers. Different TL glow peaks with varying shapes of the glow curve were observed when the dopant, the co-dopant, and the concentration of silver were altered in the samples. The TL kinetic parameters were determined, such as the order value, activation energy, and frequency factor, and the OSL parameters for the compound were also analyzed, including an exponential fit to the curves. Based on these initial results, we conclude that BioGlass has the potential for use in radiation dosimetry.
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Affiliation(s)
- Anderson M B Silva
- Departamento de Física, Universidade Federal de Sergipe, Marechal Rondon, S/N, 49.100-000, São Cristovão, SE, Brazil.
| | - Laís S Jesus
- Laboratório de Novos Materiais Nanoestruturados e Funcionais, Instituto de Física, Universidade Federal de Alagoas, 57072-900, Maceió, Alagoas, Brazil
| | - Wender Correa
- Laboratório de Novos Materiais Nanoestruturados e Funcionais, Instituto de Física, Universidade Federal de Alagoas, 57072-900, Maceió, Alagoas, Brazil
| | - Danilo O Junot
- Instituto de Física Armando Dias Tavares, Universidade do Estado do Rio de Janeiro UERJ, Rua São Francisco Xavier, 524, 20550-013, Rio de Janeiro, RJ, Brazil
| | - Linda V E Caldas
- Instituto de Pesquisas Energéticas e Nucleares, Comissão Nacional de Energia Nuclear, IPEN/CNEN-SP, Av. Prof. Lineu Prestes, 2242, 05508-000, São Paulo, SP, Brazil
| | - Noelio O Dantas
- Laboratório de Novos Materiais Nanoestruturados e Funcionais, Instituto de Física, Universidade Federal de Alagoas, 57072-900, Maceió, Alagoas, Brazil
| | - Divanizia N Souza
- Departamento de Física, Universidade Federal de Sergipe, Marechal Rondon, S/N, 49.100-000, São Cristovão, SE, Brazil
| | - Anielle C A Silva
- Laboratório de Novos Materiais Nanoestruturados e Funcionais, Instituto de Física, Universidade Federal de Alagoas, 57072-900, Maceió, Alagoas, Brazil
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Laia AS, Felix N J, Brandão-Silva AC, Rodrigues JJ, Dos Santos MAC, Dantas NO, Silva ACA, Alencar MARC. Obtaining the spectroscopic quality factor through the luminescent thermometry in 50Li 2O · 45B 2O 3 · 5Al 2O 3 glasses doped with Nd 3+ and fluorides. Appl Opt 2023; 62:C21-C29. [PMID: 37133053 DOI: 10.1364/ao.476882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Lithium-boron-aluminum (LBA) glasses doped with N d 3+ and fluorides were produced. From the absorption spectra, their Judd-Ofelt intensity parameters, Ω 2,4,6, and spectroscopic quality factors were calculated. Exploiting their near infrared temperature dependent luminescence, we investigated their potential for optical thermometry based on the luminescence intensity ratio (LIR) methodology. Three LIR schemes were proposed, and relative sensitivity values up to 3.57±0.06% K -1 were obtained. From the temperature dependent luminescence, we alternatively calculated their corresponding spectroscopic quality factors. The results indicated that N d 3+-doped LBA glasses are promising systems for optical thermometry and as gain mediums for solid-state lasers.
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Moura FBRDE, Ferreira BA, Muniz EH, Santos RA, Gomide JAL, Justino AB, Silva ACA, Dantas NO, Ribeiro DL, Araújo FA, Espindola FS, Tomiosso TC. TiO2 Nanocrystals and Annona crassiflora Polyphenols Used Alone or Mixed Impact Differently on Wound Repair. AN ACAD BRAS CIENC 2022; 94:e20210230. [PMID: 35830083 DOI: 10.1590/0001-3765202220210230] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 06/15/2021] [Indexed: 11/21/2022] Open
Abstract
Wounds treated with TiO2 nanoparticles (TiO2-NPs) show an improvement in healing time. However, little is known about the parameters that can contribute to this result. On the other hand, the treatment of wounds with polyphenols is widely known. These compounds are found in the peel of Annona crassiflora fruit and have antioxidant, analgesic and anti-inflammatory properties. In this study, we evaluated the healing effect of TiO2 nanocrystals (TiO2-NCs), polyphenolic fractions obtained from ethanolic extract of A. crassiflora fruit peel (PFAC) and mix (PFAC + TiO2-NCs) on the parameters of wound closure, inflammation, collagen deposition, metalloproteinase activity (MMPs) and angiogenesis. TiO2-NCs and PFAC have activity for wound healing, showed anti-inflammatory action and a shorter wound closure time. These treatments also contributed to increased collagen deposition, while only treatment with TiO2-NCs increased MMP-2 activity, parameters essential for the migration of keratinocytes and for complete restoration of the injured tissue. The combination of PFAC + TiO2-NCs reduced the effectiveness of individual treatments by intensifying the inflammatory process, in addition to delaying wound closure. We conclude that the interaction between the hydroxyl groups of PFAC polyphenols with TiO2-NCs may have contributed to difference in the healing activity of skin wounds.
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Affiliation(s)
- Francyelle B R DE Moura
- Universidade Federal de Uberlândia, Instituto de Ciências Biomédicas, Avenida Pará, 1720, Umuarama, 38400-902 Uberlândia, MG, Brazil.,Universidade Estadual de Campinas, Instituto de Biologia, Rua Monteiro Lobato, 255, Barão Geraldo, 13083-862 Campinas, SP, Brazil
| | - Bruno Antonio Ferreira
- Universidade Federal de Uberlândia, Instituto de Ciências Biomédicas, Avenida Pará, 1720, Umuarama, 38400-902 Uberlândia, MG, Brazil
| | - Elusca Helena Muniz
- Universidade Federal de Uberlândia, Instituto de Ciências Biomédicas, Avenida Pará, 1720, Umuarama, 38400-902 Uberlândia, MG, Brazil
| | - Rinara A Santos
- Universidade Federal de Uberlândia, Instituto de Ciências Biomédicas, Avenida Pará, 1720, Umuarama, 38400-902 Uberlândia, MG, Brazil
| | - José Augusto L Gomide
- Universidade Federal de Uberlândia, Instituto de Biotecnologia, Rua Acre, 1004, Umuarama, 38405-319 Uberlândia, MG, Brazil
| | - Allisson B Justino
- Universidade Federal de Uberlândia, Instituto de Biotecnologia, Rua Acre, 1004, Umuarama, 38405-319 Uberlândia, MG, Brazil
| | - Anielle Christine A Silva
- Universidade Federal de Alagoas, Laboratório de Novos Nanoestruturados e Funcionais, Instituto de Física, Avenida Lourival Melo Mota, s/n, Tabuleiro do Martins, 57072-900 Maceió, AL, Brazil.,Universidade Federal de Alagoas, Programa de Pós-Graduação da Rede Nordeste de Biotecnologia, Avenida Lourival Melo Mota, s/n, Tabuleiro do Martins, 57072-970 Maceió, AL, Brazil
| | - Noelio O Dantas
- Universidade Federal de Alagoas, Laboratório de Novos Nanoestruturados e Funcionais, Instituto de Física, Avenida Lourival Melo Mota, s/n, Tabuleiro do Martins, 57072-900 Maceió, AL, Brazil
| | - Daniele L Ribeiro
- Universidade Federal de Uberlândia, Instituto de Ciências Biomédicas, Avenida Pará, 1720, Umuarama, 38400-902 Uberlândia, MG, Brazil
| | - Fernanda A Araújo
- Universidade Federal de Uberlândia, Instituto de Ciências Biomédicas, Avenida Pará, 1720, Umuarama, 38400-902 Uberlândia, MG, Brazil
| | - Foued S Espindola
- Universidade Federal de Uberlândia, Instituto de Biotecnologia, Rua Acre, 1004, Umuarama, 38405-319 Uberlândia, MG, Brazil
| | - Tatiana Carla Tomiosso
- Universidade Federal de Uberlândia, Instituto de Ciências Biomédicas, Avenida Pará, 1720, Umuarama, 38400-902 Uberlândia, MG, Brazil.,Universidade Estadual de Campinas, Instituto de Biologia, Rua Monteiro Lobato, 255, Barão Geraldo, 13083-862 Campinas, SP, Brazil
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Valle AL, Silva ACA, Dantas NO, Sabino-Silva R, Melo FCC, Moreira CS, Oliveira GS, Rodrigues LP, Goulart LR. Application of ZnO Nanocrystals as a Surface-Enhancer FTIR for Glyphosate Detection. Nanomaterials (Basel) 2021; 11:nano11020509. [PMID: 33671396 PMCID: PMC7922178 DOI: 10.3390/nano11020509] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/12/2021] [Accepted: 01/13/2021] [Indexed: 11/16/2022]
Abstract
Glyphosate detection and quantification is still a challenge. After an extensive review of the literature, we observed that Fourier transform infrared spectroscopy (FTIR) had practically not yet been used for detection or quantification. The interaction between zinc oxide (ZnO), silver oxide (Ag2O), and Ag-doped ZnO nanocrystals (NCs), as well as that between nanocomposite (Ag-doped ZnO/AgO) and glyphosate was analyzed with FTIR to determine whether nanomaterials could be used as signal enhancers for glyphosates. The results were further supported with the use of atomic force microscopy (AFM) imaging. The glyphosate commercial solutions were intensified 10,000 times when incorporated the ZnO NCs. However, strong chemical interactions between Ag and glyphosate may suppress signaling, making FTIR identification difficult. In short, we have shown for the first time that ZnO NCs are exciting tools with the potential to be used as signal amplifiers of glyphosate, the use of which may be explored in terms of the detection of other molecules based on nanocrystal affinity.
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Affiliation(s)
- Anderson L. Valle
- Nanobiotechnology Laboratory, Institute of Genetics and Biochemistry, Federal University of Uberlândia, Uberlândia 38402-022, MG, Brazil; (A.L.V.); (F.C.C.M.)
| | - Anielle C. A. Silva
- Laboratory of New Insulating and Semiconductors Materials, Institute of Physics, Federal University of Uberlândia, Uberlândia 38408-100, MG, Brazil;
- Laboratory of New Nanostructured and Functional Materials, Institute of Physics, Federal University of Alagoas, Maceió 57072-970, AL, Brazil
- Correspondence: (A.C.A.S.); (L.R.G.); Tel.: +82-3214-1000 (A.C.A.S.); +34-3225-8440 (L.R.G.)
| | - Noelio O. Dantas
- Laboratory of New Insulating and Semiconductors Materials, Institute of Physics, Federal University of Uberlândia, Uberlândia 38408-100, MG, Brazil;
- Laboratory of New Nanostructured and Functional Materials, Institute of Physics, Federal University of Alagoas, Maceió 57072-970, AL, Brazil
| | - Robinson Sabino-Silva
- Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia 38402-022, MG, Brazil;
| | - Francielli C. C. Melo
- Nanobiotechnology Laboratory, Institute of Genetics and Biochemistry, Federal University of Uberlândia, Uberlândia 38402-022, MG, Brazil; (A.L.V.); (F.C.C.M.)
| | - Cleumar S. Moreira
- Electrical Engineering Department, Federal Institute of Paraíba, João Pessoa 58015-020, PB, Brazil;
| | - Guedmiller S. Oliveira
- Institute of Chemistry, Federal University of Uberlândia, Uberlândia 38402-022, MG, Brazil;
| | - Luciano P. Rodrigues
- Institute of Engineering, Science and Technology, Federal University of Jequitinhonha and Mucuri’s Valleys, Janaúba 39447-814, MG, Brazil;
| | - Luiz R. Goulart
- Nanobiotechnology Laboratory, Institute of Genetics and Biochemistry, Federal University of Uberlândia, Uberlândia 38402-022, MG, Brazil; (A.L.V.); (F.C.C.M.)
- Correspondence: (A.C.A.S.); (L.R.G.); Tel.: +82-3214-1000 (A.C.A.S.); +34-3225-8440 (L.R.G.)
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Martins BR, Barbosa YO, Andrade CMR, Pereira LQ, Simão GF, de Oliveira CJ, Correia D, Oliveira RTS, da Silva MV, Silva ACA, Dantas NO, Rodrigues V, Muñoz RAA, Alves-Balvedi RP. Development of an Electrochemical Immunosensor for Specific Detection of Visceral Leishmaniasis Using Gold-Modified Screen-Printed Carbon Electrodes. Biosensors (Basel) 2020; 10:bios10080081. [PMID: 32717832 PMCID: PMC7460044 DOI: 10.3390/bios10080081] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/14/2020] [Accepted: 07/17/2020] [Indexed: 12/20/2022]
Abstract
Visceral leishmaniasis is a reemerging neglected tropical disease with limitations for its diagnosis, including low concentration of antibodies in the serum of asymptomatic patients and cross-reactions. In this context, this work proposes an electrochemical immunosensor for the diagnosis of visceral leishmaniasis in a more sensitive way that is capable of avoiding cross-reaction with Chagas disease (CD). Crude Leishmania infantum antigens tested in the enzyme-linked immunosorbent assay (ELISA) were methodologically standardized to best engage to the sensor. The antibodies anti-Trypanosoma cruzi and anti-Leishmania sp. Present in serum from patients with diverse types of CD or leishmaniasis were chosen. A screen-printed carbon electrode modified with gold nanoparticles was the best platform to guarantee effective adsorption of all antigens so that the epitope of specific recognition for leishmaniasis occurred efficiently and without cross-reaction with the evaluated CD. The current peaks reduced linearly after the recognition, and still were able to notice the discrimination between different kinds of diseases (digestive, cardiac, undetermined Chagas/acute and visceral chronic leishmaniasis). Comparative analyses with ELISA were performed with the same groups, and a low specificity (44%) was verified due to cross-reactions (high number of false positives) on ELISA tests, while the proposed immunosensor presented high selectivity and specificity (100%) without any false positives or false negatives for the serum samples from isolated patients with different types of CD and visceral leishmaniasis. Furthermore, the biosensor was stable for 5 days and presented a detection limit of 200 ng mL−1.
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Affiliation(s)
- Beatriz R. Martins
- Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba-MG 38025-180, Brazil; (B.R.M.); (Y.O.B.); (C.J.d.O.); (R.T.S.O.J.); (V.R.J.)
| | - Yanne O. Barbosa
- Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba-MG 38025-180, Brazil; (B.R.M.); (Y.O.B.); (C.J.d.O.); (R.T.S.O.J.); (V.R.J.)
| | - Cristhianne M. R. Andrade
- Institute of Health Sciences, Federal University of Triângulo Mineiro, Uberaba-MG 38025-180, Brazil; (C.M.R.A.); (L.Q.P.); (D.C.); (M.V.d.S.)
| | - Loren Q. Pereira
- Institute of Health Sciences, Federal University of Triângulo Mineiro, Uberaba-MG 38025-180, Brazil; (C.M.R.A.); (L.Q.P.); (D.C.); (M.V.d.S.)
| | - Guilherme F. Simão
- Institute of Technological and Exact Sciences, Federal University of Triângulo Mineiro, Uberaba-MG 38025-180, Brazil;
| | - Carlo J. de Oliveira
- Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba-MG 38025-180, Brazil; (B.R.M.); (Y.O.B.); (C.J.d.O.); (R.T.S.O.J.); (V.R.J.)
- Institute of Health Sciences, Federal University of Triângulo Mineiro, Uberaba-MG 38025-180, Brazil; (C.M.R.A.); (L.Q.P.); (D.C.); (M.V.d.S.)
| | - Dalmo Correia
- Institute of Health Sciences, Federal University of Triângulo Mineiro, Uberaba-MG 38025-180, Brazil; (C.M.R.A.); (L.Q.P.); (D.C.); (M.V.d.S.)
| | - Robson T. S. Oliveira
- Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba-MG 38025-180, Brazil; (B.R.M.); (Y.O.B.); (C.J.d.O.); (R.T.S.O.J.); (V.R.J.)
| | - Marcos V. da Silva
- Institute of Health Sciences, Federal University of Triângulo Mineiro, Uberaba-MG 38025-180, Brazil; (C.M.R.A.); (L.Q.P.); (D.C.); (M.V.d.S.)
| | - Anielle C. A. Silva
- Institute of Physics, Federal University of Alagoas, Maceio-AL 57072-970, Brazil; (A.C.A.S.); (N.O.D.)
| | - Noelio O. Dantas
- Institute of Physics, Federal University of Alagoas, Maceio-AL 57072-970, Brazil; (A.C.A.S.); (N.O.D.)
| | - Virmondes Rodrigues
- Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba-MG 38025-180, Brazil; (B.R.M.); (Y.O.B.); (C.J.d.O.); (R.T.S.O.J.); (V.R.J.)
- Institute of Health Sciences, Federal University of Triângulo Mineiro, Uberaba-MG 38025-180, Brazil; (C.M.R.A.); (L.Q.P.); (D.C.); (M.V.d.S.)
| | - Rodrigo A. A. Muñoz
- Institute of Chemistry, Federal University of Uberlândia, Uberlândia-MG 38408-100, Brazil
- Correspondence: (R.A.A.M.); (R.P.A.-B.)
| | - Renata P. Alves-Balvedi
- Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba-MG 38025-180, Brazil; (B.R.M.); (Y.O.B.); (C.J.d.O.); (R.T.S.O.J.); (V.R.J.)
- Federal University of Triângulo Mineiro, Iturama-MG 38025-180, Brazil
- Correspondence: (R.A.A.M.); (R.P.A.-B.)
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Dias EHV, Pereira DFC, de Sousa BB, Matias MS, de Queiroz MR, Santiago FM, Silva ACA, Dantas NO, Santos-Filho NA, de Oliveira F. In vitro tracking of phospholipase A 2 from snake venom conjugated with magic-sized quantum dots. Int J Biol Macromol 2018; 122:461-468. [PMID: 30385337 DOI: 10.1016/j.ijbiomac.2018.10.185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 08/20/2018] [Accepted: 10/27/2018] [Indexed: 01/09/2023]
Abstract
Phospholipases A2 represent a family of enzymes with important application in medicine. However, direct tracking is difficult due to the absence of a stable, effective and specific marker for these enzymes. Magic-sized quantum dots (MSQDs) are inorganic semiconducting nanocrystals with unique physical properties. They have the ability to conjugate to proteins, making them excellent markers for biological systems. In this work, we labelled phospholipase A2 from Bothrops alternatus snake venom with Cadmium selenide (CdSe)/cadmium sulphate (CdS) MSQDs-a biocompatible and luminescent probe-. Bioconjugation was confirmed using infrared spectra and fluorescence microscopy, which demonstrated that the CdSe/CdS MSQDs interact with phospholipase A2 without interfering with its activity. This probe may be an important tool for the elucidation of many biological mechanisms, because it allows the pathway of phospholipase A2 to be tracked from its entry through the plasma membrane until its incorporation into the nucleus of myoblasts.
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Affiliation(s)
- Edigar H V Dias
- Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Déborah F C Pereira
- Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Bruna B de Sousa
- Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil; Instituto de Química, Universidade Estadual Paulista, Araraquara, SP, Brazil
| | - Mariana S Matias
- Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Mayara R de Queiroz
- Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil; Instituto Nacional de Ciência e Tecnologia em Nano-Biofarmacêutica (N-Biofar), Belo Horizonte, MG, Brazil
| | - Fernanda M Santiago
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Anielle C A Silva
- Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Noelio O Dantas
- Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | | | - Fábio de Oliveira
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil; Instituto Nacional de Ciência e Tecnologia em Nano-Biofarmacêutica (N-Biofar), Belo Horizonte, MG, Brazil.
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Silva AS, Lourenço SA, da Silva MAT, da Silva SW, Morais PC, Dantas NO. Effect of Co co-doping on the optical properties of ZnTe:Mn nanocrystals. Phys Chem Chem Phys 2017; 19:1158-1166. [PMID: 27942619 DOI: 10.1039/c6cp05866c] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We study the effect of Co co-doping on the optical properties of Mn-doped ZnTe nanocrystals (NCs) embedded in a glass matrix. Optical absorption (OA) and crystal field theory strongly indicated the substitutional incorporation of Co2+ ions into these semiconducting NCs as well as the characteristic transitions of these ions in the visible and near infrared spectral region. Transmission electron microscopy (TEM) images revealed an invariant NC lattice parameter with the incorporation of Mn2+ and Co2+ ions. The same was confirmed by X-ray diffraction (XRD). The photoluminescence (PL) spectra showed that the characteristic emission bands of Co2+ ions (E1Co2+ and E2Co2+) are intense and evident at low temperatures. Indeed, Raman spectra showed that the dependence of luminescence intensity on temperature is due to the electron-phonon interaction that arises from multiphonon relaxation processes. The redshifts in the PL spectra from green to orange with the incorporation of Mn2+ ions into ZnTe NCs, and in the near infrared with increasing Co-concentration, result from sp-d exchange interactions associated with the increase in Mn2+ and Co2+ ions in tetrahedral sites of ZnTe NCs, which may be very interesting for applications in luminescent devices. These observations provide strong evidence that higher Co-concentrations inhibit the incorporation of Mn2+ into ZnTe NCs, suggesting that there may be competition between Co2+ and Mn2+ ions substituting Zn2+ ions and, furthermore, that these ions replace zinc vacancies (VZn) in these NCs.
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Affiliation(s)
- Alessandra S Silva
- Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, 38400-902, Brazil.
| | - Sidney A Lourenço
- Departamento Acadêmico de Física, Universidade Tecnológica Federal do Paraná, CEP 86036-370, Londrina, Paraná, Brazil
| | - Marco A T da Silva
- Departamento Acadêmico de Física, Universidade Tecnológica Federal do Paraná, CEP 86036-370, Londrina, Paraná, Brazil
| | | | - Paulo C Morais
- Instituto de Física, Universidade de Brasília, Brasília, 70910-900, Brazil and School of Chemistry and Chemical Engineering, Anhui University, 230601 Hefei, China
| | - Noelio O Dantas
- Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, 38400-902, Brazil.
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Goto TE, Lopes CC, Nader HB, Silva AC, Dantas NO, Siqueira JR, Caseli L. CdSe magic-sized quantum dots incorporated in biomembrane models at the air–water interface composed of components of tumorigenic and non-tumorigenic cells. Biochimica et Biophysica Acta (BBA) - Biomembranes 2016; 1858:1533-40. [DOI: 10.1016/j.bbamem.2016.04.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 04/08/2016] [Accepted: 04/19/2016] [Indexed: 10/21/2022]
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Silva AS, Lourenço SA, Dantas NO. Mn concentration-dependent tuning of Mn(2+) d emission of Zn1-xMnxTe nanocrystals grown in a glass system. Phys Chem Chem Phys 2016; 18:6069-76. [PMID: 26844704 DOI: 10.1039/c5cp06802a] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We studied the effect of Mn concentration on the optical, morphological and magnetic properties of Zn1-xMnxTe NCs grown in a glass matrix produced by the fusion method. The physical properties of these materials were determined by optical absorption (OA), transmission electron microscopy (TEM), atomic/magnetic force microscopy (AFM/MFM) and photoluminescence (PL). An analysis of the OA spectra, based on the crystal field theory (CFT), showed strong evidence that Mn(2+) ions were substitutionally incorporated into the Zn1-xMnxTe NCs until reaching the solubility limit (concentration, x = 0.100). Above this nominal concentration, TEM showed the onset of Mn-related phases, such as MnO and α-MnO2, in the PZABP glass system. AFM images showed that NC density on the surface of the glass matrix decreased as x-content increased. It is probable that MnO and MnO2 NCs would outnumber Zn1-xMnxTe NCs at higher concentrations - a conclusion that was corroborated by the OA spectra and TEM images. MFM images revealed that samples with Mn(2+) ions responded to magnetization from an MFM probe. This implied that Mn(2+) ions were incorporated within the Zn1-xMnxTe NCs and gave rise to the diluted magnetic semiconductor (DMS) structure. The PL spectra not only confirmed the evidence obtained by OA, CFT, TEM and AFM/MFM, but also showed that Mn(2+) concentration could be used to tune (4)T1((4)G) → (6)A1((6)S) emission energy.
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Affiliation(s)
- Alessandra S Silva
- Universidade Federal de Uberlândia, Instituto de Física, Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Uberlândia, CEP 38400-902, Brazil.
| | - Sidney A Lourenço
- Universidade Tecnológica Federal do Paraná, Engenharia de Materiais, CEP 86036-370, Londrina, Paraná, Brazil
| | - Noelio O Dantas
- Universidade Federal de Uberlândia, Instituto de Física, Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Uberlândia, CEP 38400-902, Brazil.
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Silva AS, Pelegrini F, Figueiredo LC, de Souza PEN, da Silva SW, de Morais PC, Dantas NO. Evidence of competition in the incorporation of Co2+and Mn2+ions into the structure of ZnTe nanocrystals. RSC Adv 2016. [DOI: 10.1039/c6ra19189d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Glass-embedded Zn1−x−yMnxCoyTe nanocrystals (withx= 0.01 andyvarying from 0.000 to 0.800) were successfully synthesized using a protocol based on the melting–nucleation synthesis route and herein investigated by several experimental techniques.
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Affiliation(s)
- Alessandra S. Silva
- Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS)
- Instituto de Física
- Universidade Federal de Uberlândia
- Uberlândia
- Brazil
| | | | | | | | | | - Paulo C. de Morais
- Instituto de Física
- Universidade de Brasília
- Brasília
- Brazil
- School of Chemistry and Chemical Engineering
| | - Noelio O. Dantas
- Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS)
- Instituto de Física
- Universidade Federal de Uberlândia
- Uberlândia
- Brazil
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Lourenço SA, Silva RS, Dantas NO. Tunable dual emission in visible and near-infrared spectra using Co2+-doped PbSe nanocrystals embedded in a chalcogenide glass matrix. Phys Chem Chem Phys 2016; 18:23036-43. [DOI: 10.1039/c6cp04419k] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Emission of Co2+-doped PbSe nanocrystals (NCs) present a excited-state crossover from 4T1(P) → 4A2(F) broadband emission to 2E(G) → 4A2(F) narrow-line emission, and its localized energy transition (4A2(F) → 4T1(4F)) can be tunable from band-gap to the conduction-band by change NC size.
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Affiliation(s)
- Sidney A. Lourenço
- Departamento Acadêmico de Física
- Universidade Tecnológica Federal do Paraná – UTFPR
- Londrina
- Brazil
| | - Ricardo S. Silva
- Departamento de Física
- Universidade Federal do Triângulo Mineiro
- Uberaba
- Brazil
| | - Noelio O. Dantas
- Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS)
- Instituto de Física
- Universidade Federal de Uberlândia
- Uberlândia
- Brazil
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de Santana JF, Pilla V, Silva ACA, Dantas NO, Messias DN, Andrade AA. Optical characterization of core-shell quantum dots embedded in synthetic saliva: Temporal dynamics. J Photochem Photobiol B 2015; 151:208-12. [PMID: 26313857 DOI: 10.1016/j.jphotobiol.2015.08.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 07/19/2015] [Accepted: 08/14/2015] [Indexed: 10/23/2022]
Abstract
The present work reports the spectroscopic and thermo-optical properties of CdSe/ZnS and CdSe/CdS core-shell quantum dots (QDs) embedded in synthetic saliva. Spectroscopy studies were performed applying nonfunctionalized CdSe/ZnS QDs (3.4, 3.9 and 5.1 nm cores) and hydroxyl group-functionalized ultrasmall CdSe/CdS core-shell quantum dots (1.6 nm core) suspended in artificial saliva at different potential of hydrogen (pH) values. Saliva was chosen because it is important in a variety of functions such as protecting teeth through the buffering capacity of the formed biofilm, hydration, and dental remineralization. Thermo-optical characterizations using the thermal lens (TL) technique were performed in QD-biofluids for different QD sizes and pH values (3.9-8.3) of the synthetic oral fluids. Transient TL measurements were applied to determine the fluorescence quantum efficiency (η) in QD-biomaterial systems. High η value was obtained for ultrasmall CdSe/CdS QDs. Fluorescence spectral measurements of the biomaterials support the TL results. In addition, for nonfunctionalized (3.4 and 5.1 nm) and hydroxyl group-functionalized QDs, the temporal behavior of the fluorescence spectra was accomplished about approximately 1200 h at two different biofluid pH values (3.9 and 8.3). The temporal fluorescence intensity result is dependent on the pH of the saliva in which the QDs were embedded, QD functionalization and QD sizes. The time for an approximately 50% decrease in the peak intensity fluorescence of CdSe/ZnS QDs (3.4 nm core) and ultrasmall CdSe/CdS QDs is respectively 25 h and 312 h at pH 3.9 and 48 h and 360 h at pH 8.3.
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Affiliation(s)
- Juliana F de Santana
- Grupo de Propriedades Ópticas e Térmicas de Materiais (GPOTM), Instituto de Física, Universidade Federal de Uberlândia - UFU, Av. João Naves de Ávila 2121, Uberlândia, MG 38400-902, Brazil
| | - Viviane Pilla
- Grupo de Propriedades Ópticas e Térmicas de Materiais (GPOTM), Instituto de Física, Universidade Federal de Uberlândia - UFU, Av. João Naves de Ávila 2121, Uberlândia, MG 38400-902, Brazil.
| | - Anielle C A Silva
- Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberlândia - UFU, Av. João Naves de Ávila 2121, Uberlândia, MG 38400-902, Brazil
| | - Noelio O Dantas
- Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberlândia - UFU, Av. João Naves de Ávila 2121, Uberlândia, MG 38400-902, Brazil
| | - Djalmir N Messias
- Grupo de Propriedades Ópticas e Térmicas de Materiais (GPOTM), Instituto de Física, Universidade Federal de Uberlândia - UFU, Av. João Naves de Ávila 2121, Uberlândia, MG 38400-902, Brazil
| | - Acácio A Andrade
- Grupo de Propriedades Ópticas e Térmicas de Materiais (GPOTM), Instituto de Física, Universidade Federal de Uberlândia - UFU, Av. João Naves de Ávila 2121, Uberlândia, MG 38400-902, Brazil
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Bernardino FDC, Lourenço SA, Da Silva MAT, Dantas NO. Estudo das propriedades ópticas de vidros borosilicatos dopados com íons de Itérbio em função da concentração. Semina: Tech Ex 2015. [DOI: 10.5433/1679-0375.2015v36n1p19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Silva AS, Lourenço SA, Pereira-da-Silva MA, Duarte JL, Renzi W, Alcalde AM, Dantas NO. Annealing time on carrier dynamics of ZnTe nanoparticles embedded in a near ultraviolet-transparent glass. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2014.03.039] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Silva ACA, da Silva SW, Morais PC, Dantas NO. Shell thickness modulation in ultrasmall CdSe/CdS(x)Se(1-x)/CdS core/shell quantum dots via 1-thioglycerol. ACS Nano 2014; 8:1913-1922. [PMID: 24460449 DOI: 10.1021/nn406478f] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this study, we report on the synthesis of CdSe/CdS core-shell ultrasmall quantum dots (CS-USQDs) using an aqueous-based wet chemistry protocol. The proposed chemical route uses increasing concentration of 1-thioglycerol to grow the CdS shell on top of the as-precipitated CdSe core in a controllable way. We found that lower concentration of 1-thioglycerol (3 mmol) added into the reaction medium limits the growth of the CdSe core, and higher and increasing concentration (5-11 mmol) of 1-thioglycerol promotes the growth of CdS shell on top of the CdSe core in a very controllable way, with an increase from 0.50 to 1.25 nm in shell thickness. The growth of CS-USQDs of CdSe/CdS was confirmed by using different experimental techniques, such as optical absorption (OA) spectroscopy, fluorescence spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and Raman spectroscopy. Data collected from OA were used to obtain the average values of the CdSe core diameter, whereas Raman data were used to assess the average values of the CdSe core diameter and CdS shell thicknesses.
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Affiliation(s)
- Anielle Christine A Silva
- Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Institute of Physics, Federal University of Uberlândia , CP 593, Uberlândia MG 38400-902, Brazil
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Gasparotto LHS, Castelhano ALB, Silva ACA, Dantas NO, Oliveira ON, Siqueira JR. Dendrimer–carbon nanotube layer-by-layer film as an efficient host matrix for electrogeneration of PtCo electrocatalysts. Phys Chem Chem Phys 2014; 16:2384-9. [DOI: 10.1039/c3cp54296c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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17
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Serqueira EO, Dantas NO. Luminescence of Nd3+ ions under excitation of CdSe quantum dots in a glass system: energy transfer. Opt Lett 2014; 39:131-134. [PMID: 24365840 DOI: 10.1364/ol.39.000131] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We report rare evidence of energy transfer from CdSe quantum dots (QDs) to Nd3+ ions in a SNAB glass system using absorption electronic transitions of ion as a nonresonant excitation source. However, the luminescence band was observed at 880 nm (4F3/2→4I9/2 transition) under 409 nm excitation only when Nd3+ ions were embedded in the SNAB glass system with CdSe QDs. This happened because the Nd3+ ions absorbed the photons emitted by CdSe QDs with 409 nm excitation. Band overlap of the QD luminescence band and the ion optical absorption bands caused photon absorption and produced valleys in the QD luminescence spectrum. This overlap contributed to reduction in the lifetime 4F3/2 state.
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Andrade AA, Lourenço SA, Pilla V, Silva ACA, Dantas NO. Evidence of phase transition in Nd3+doped phosphate glass determined by thermal lens spectrometry. Phys Chem Chem Phys 2014; 16:1583-9. [DOI: 10.1039/c3cp54206h] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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19
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Pilla V, de Lima SR, Andrade AA, Silva AC, Dantas NO. Fluorescence quantum efficiency of CdSe/CdS magic-sized quantum dots functionalized with carboxyl or hydroxyl groups. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2013.07.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Gasparotto LHS, Castelhano ALB, Gabriel RC, Dantas NO, Oliveira ON, Siqueira JR. Electrogeneration of platinum nanoparticles in a matrix of dendrimer–carbon nanotubes. Phys Chem Chem Phys 2013; 15:17887-92. [DOI: 10.1039/c3cp52707g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Freitas Neto ES, Dantas NO, da Silva SW, Morais PC, Pereira-da-Silva MA, Moreno AJD, López-Richard V, Marques GE, Trallero-Giner C. Temperature-dependent Raman study of thermal parameters in CdS quantum dots. Nanotechnology 2012; 23:125701. [PMID: 22397807 DOI: 10.1088/0957-4484/23/12/125701] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report on the strong temperature-dependent thermal expansion, α(D), in CdS quantum dots (QDs) embedded in a glass template. We have performed a systematic study by using the temperature-dependent first-order Raman spectra, in CdS bulk and in dot samples, in order to assess the size dependence of α(D), and where the role of the compressive strain provoked by the glass host matrix on the dot response is discussed. We report the Grüneisen mode parameters and the anharmonic coupling constants for small CdS dots with mean radius R ∼ 2.0 nm. We found that γ parameters change, with respect to the bulk CdS, in a range between 20 and 50%, while the anharmonicity contribution from two-phonon decay channel becomes the most important process to the temperature-shift properties.
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Affiliation(s)
- E S Freitas Neto
- Laboratório de Novos Materiais Isolantes e Semicondutores, Instituto de Física, Universidade Federal de Uberlândia, 38400-902 Uberlândia, Minas Gerais, Brazil.
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Siqueira JR, Gabriel RC, Zucolotto V, Silva ACA, Dantas NO, Gasparotto LHS. Electrodeposition of catalytic and magnetic gold nanoparticles on dendrimer–carbon nanotube layer-by-layer films. Phys Chem Chem Phys 2012; 14:14340-3. [DOI: 10.1039/c2cp42813j] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Lourenço SA, Dantas NO, Silva RS. Growth kinetic on the optical properties of the Pb1−xMnxSe nanocrystals embedded in a glass matrix: thermal annealing and Mn2+ concentration. Phys Chem Chem Phys 2012; 14:11040-7. [DOI: 10.1039/c2cp40850c] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Dantas NO, Silva AS, Freitas Neto ES, Lourenço SA. Thermal activated energy transfer between luminescent states of Mn2+-doped ZnTe nanoparticles embedded in a glass matrix. Phys Chem Chem Phys 2012; 14:3520-9. [DOI: 10.1039/c2cp23681h] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Noelio O Dantas
- Universidade Federal de Uberlândia, Instituto de Física, Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Uberlândia, CEP 38400-902, Brazil.
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Neto ESF, Dantas NO, Lourenço SA. Carrier dynamics in the luminescent states of Cd1−xMnxS nanoparticles: effects of temperature and x-concentration. Phys Chem Chem Phys 2012; 14:1493-501. [DOI: 10.1039/c1cp23106e] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Freitas Neto ES, Dantas NO, Lourenço SA, Teodoro MD, Marques GE. Magneto-optical properties of Cd1−xMnxS nanoparticles: influences of magnetic doping, Mn2+ ions localization, and quantum confinement. Phys Chem Chem Phys 2012; 14:3248-55. [DOI: 10.1039/c2cp23492k] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Dantas NO, Ayta WEF, Silva ACA, Cano NF, Silva SW, Morais PC. Effect of Fe2O3 concentration on the structure of the SiO2-Na2O-Al2O3-B2O3 glass system. Spectrochim Acta A Mol Biomol Spectrosc 2011; 81:140-143. [PMID: 21763184 DOI: 10.1016/j.saa.2011.05.074] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 05/14/2011] [Accepted: 05/24/2011] [Indexed: 05/31/2023]
Abstract
The structural properties of the glass matrix 40SiO(2)·30Na(2)O·1Al(2)O(3)·(29-x)B(2)O(3)·xFe(2)O(3) (mol%), 0.0≤x≤29.0 were studied by X-ray diffraction (XRD), differential thermal analysis (DTA) and Raman and infrared spectroscopy (FT-IR). XRD demonstrated Fe(3)O(4) crystal formation for Fe(2)O(3) concentrations of 29.0 mol%. DTA showed that glass transition and crystallization temperatures changed as a function of Fe(2)O(3) concentration and that these alterations were related to structural change in the glass system. Interesting aspects of Raman and FT-IR spectra were found, and this gives information about of the structure changes in Si-O-Si units of these glasses as a function of Fe(2)O(3) concentration.
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Affiliation(s)
- Noelio O Dantas
- Laboratório de Novos Materiais Isolantes e Semicondutores, Instituto de Física, Universidade Federal de Uberlândia, CEP 38400-902, Uberlândia, MG, Brazil.
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Freitas Neto ES, Dantas NO, Barbosa Neto NM, Guedes I, Chen F. Control of luminescence emitted by Cd 1-x Mn x S nanocrystals in a glass matrix: x concentration and thermal annealing. Nanotechnology 2011; 22:105709. [PMID: 21289403 DOI: 10.1088/0957-4484/22/10/105709] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Cd(1-x)Mn(x)S nanocrystals (NCs) were successfully grown in a glass matrix and investigated by photoluminescence (PL), electron paramagnetic resonance (EPR) and magnetic force microscopy (MFM). We verified that the luminescent properties of these NCs can be controlled both by changing the x concentration and by thermal annealing of the samples. The EPR and PL data showed that the characteristic emission of Mn(2+) ions ((4)T(1)-(6)A(1)) is only observed when this magnetic impurity is substitutionally incorporated in the Cd(1-x)Mn(x)S NC core (site S(I)). Besides, it was observed that the emission ((4)T(1)-(6)A(1)) suppression, caused by the Mn(2+) ion presence near the surface (site S(II)) of the Cd(1-x)Mn(x)S NCs, is independent of the host material. The MFM images also confirmed the high quality of the Cd(1 - x)Mn(x)S NC samples, showing a uniform distribution of total magnetic moments in the nanoparticles.
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Affiliation(s)
- Ernesto S Freitas Neto
- Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberlândia, CP 593, CEP 38400-902, Uberlândia, Minas Gerais, Brazil.
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Dantas NO, Serqueira EO, Carmo AP, Bell MJV, Anjos V, Marques GE. Energy transfer between CdS nanocrystals and neodymium ions embedded in vitreous substrates. Opt Lett 2010; 35:1329-1331. [PMID: 20436558 DOI: 10.1364/ol.35.001329] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Experimental evidence has been observed for energy transfer from CdS nanocrystals, synthesized by the fusion method, to Nd(3+) ions embedded in vitreous substrates. These dot samples doped with neodymium have been investigated by combined optical absorption (OA), photoluminescence (PL), and time-resolved photoluminescence (PLRT) techniques. Radiative and nonradiative energy transfers between CdS dot and Nd(3+) ion levels, to our knowledge not reported before, can be clearly observed in the PL spectra where the emission band valleys correspond exactly to the energy absorption peaks of the doping ion. The PLRT data reinforce these energy transfer mechanisms in which the increasing overlap between the CdS PL band and the OA to the Nd(3+) levels decreases stimulated emissions from the doping ions.
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Affiliation(s)
- N O Dantas
- Laboratório de Novos Materiais Isolantes e Semicondutores-LNMIS, Instituto de Física, Universidade Federal de Uberlândia, 38400-902, Uberlândia, Minas Gerais, Brazil
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Melo RM, Dantas NO, Souza NCD, Oliveira Jr. ON, Faria RM, Marletta A. Formação e caracterização óptica de filmes automontados de POMA/PPV. QUIM NOVA 2003. [DOI: 10.1590/s0100-40422003000200006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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