Structural characterization and plasmonic properties of manganese oxide-coated gold nanorods.

Autor: Marques FC; Laboratório de Nanoestruturas Plasmônicas, Núcleo de Espectroscopia e Estrutura Molecular, Centro de Estudos de Materiais (CEM), Departamento de Química, Universidade Federal de Juiz de Fora, R. José Lourenço Kelmer, s/n, 36036-900 Juiz de Fora, MG, Brazil. Electronic address: flavia@ice.ufjf.br., Azevedo GC; Núcleo de Pesquisa em Instrumentação e Separações Analíticas (NUPIS), Departamento de Química, Universidade Federal de Juiz de Fora, Juiz de Fora, MG, Brazil., Senna CA; Divisão de Metrologia de Materiais, Instituto Nacional de Metrologia, Qualidade e Tecnologia, Xerém-Duque de Caxias, RJ, Brazil., Archanjo BS; Divisão de Metrologia de Materiais, Instituto Nacional de Metrologia, Qualidade e Tecnologia, Xerém-Duque de Caxias, RJ, Brazil., Corrêa CC; Grupo de Pesquisa em Química dos Materiais Porosos (GPQMAP), Departamento de Química, Universidade Federal de Juiz de Fora, Juiz de Fora, MG, Brazil., Matos RC; Núcleo de Pesquisa em Instrumentação e Separações Analíticas (NUPIS), Departamento de Química, Universidade Federal de Juiz de Fora, Juiz de Fora, MG, Brazil., Dos Santos DP; Departamento de Físico-Química, Instituto de Química, Universidade Estadual de Campinas, Campinas, SP, Brazil., Andrade GFS; Laboratório de Nanoestruturas Plasmônicas, Núcleo de Espectroscopia e Estrutura Molecular, Centro de Estudos de Materiais (CEM), Departamento de Química, Universidade Federal de Juiz de Fora, R. José Lourenço Kelmer, s/n, 36036-900 Juiz de Fora, MG, Brazil. Electronic address: gustavo.andrade@ufjf.edu.br.
Jazyk: angličtina
Zdroj: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy [Spectrochim Acta A Mol Biomol Spectrosc] 2022 May 05; Vol. 272, pp. 120988. Date of Electronic Publication: 2022 Feb 03.
DOI: 10.1016/j.saa.2022.120988
Abstrakt: The preparation of metal@(dielectric or semiconductor) core@shell hybrid materials have been shown promising for both SERS and SEF applications due to improved stability in the presence of ions and the adsorbate compared to non-covered metallic nanoparticles. However, fine control over the thickness of the covering layer is essential to maximize the intrinsic trade-off between the plasmonic enhancement and the chemical stability improvement. Here, the preparation of manganese dioxide ultrathin layers covered gold nanorods (AuNR@MnO 2 ) with varying thicknesses of the MnO 2 layer is reported, and the characterization and evaluation of the resulting materials as SERS and SEF substrate. The MnO 2 layer over the AuNR was prepared by reducing potassium permanganate by sodium oxalate in a basic medium. The AuNR@MnO 2 hybrid material was characterized by UV-Vis spectroscopy, transmission electron microscopy, X-ray powder diffraction, and cyclic voltammetry. It was studied the SEF effect of the cyanine dye IR-820 excited at 785 nm with high performance for several thicknesses of the MnO 2 ultrathin film. The enhancement factor increased for thicker oxide layers. The SERS effect of the IR-820 dye excited at 633 nm showed the most significant enhancement factor for thinner layers. The seemly opposite behavior of the two plasmonic effects may be assigned to the distance dependence of the electromagnetic field generated in the AuNR, which results in decreasing SERS performance. For SEF, the thinner layers resulted in the Au nanoparticles' emission quenching, so a more significant distance was necessary to observe enhancement.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: