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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Study of the energy transfer process in rare earth-doped silk fibroin for future application in luminescent compounds

Texto completo
Pugina, Roberta S. [1] ; da Rocha, Euzane G. [1] ; Ribeiro, Sidney J. L. [2] ; Caiut, Jose Mauricio A. [1]
Número total de Autores: 4
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Quim, Av Bandeirantes 3900, BR-14040901 Ribeirao Preto, SP - Brazil
[2] Sao Paulo State Univ, Inst Chem, UNESP, BR-14801970 Araraquara, SP - Brazil
Número total de Afiliações: 2
Tipo de documento: Artigo Científico
Fonte: Journal of Luminescence; v. 205, p. 423-428, JAN 2019.
Citações Web of Science: 2

The use of rare earth (RE)-doped materials in photonics; e.g., in solid-state lasers in the UV-vis NIR spectral region, in light emitting devices, and in fibers for optical amplifiers and data storage systems, is well known. Combining the mechanical and optical properties of silk fibroin (SF) with the multifunctionality of rare earth ions could be an interesting strategy to develop new, distinguished photonic devices. For this reason and given that no studies about light emission in RE-doped silk fibroin exist, here we present an innovative approach to develop photonic devices based on SF doped with RE ions, and we employ europium ion as a structural probe in a RE-doped composite SF matrix to obtain systems with better emission parameters. To this end, we prepared self-supported films consisting of RE-doped SF. The Bombyx mori SF bears aromatic amino acids, such as Tyrosine (Tyr) and Tryptophan (Trp), which display fluorescent behavior. These amino acids can function as fluorescent probes of physicochemical properties. In the presence of RE ions, these amino acids can act as sensitizer in energy transfer processes. Our results revealed RE ion emission associated with an antenna effect elicited by the aromatic amino acids. We verified distinct photophysical properties for different RE ions. To understand the process, we determined the triplet state of Trp in SF, which helped to describe the energy process. The energy of the Trp triplet state allowed quite efficient energy transfer from Trp to the Tb3+ ion. In conclusion, this research work improved our understanding of the mechanism of RE ion excitation in SF matrix. The present results will support future work on the development of new photonic systems. (AU)

Beneficiário:José Maurício Almeida Caiut
Linha de fomento: Auxílio à Pesquisa - Regular