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. 2022 Feb 28;12(1):3341.
doi: 10.1038/s41598-022-07200-9.

Synthesis and defect characterization of hybrid ceria nanostructures as a possible novel therapeutic material towards COVID-19 mitigation

L S R Rocha  1 , A Z Simões  2 , C Macchi  3 , A Somoza  3 , G Giulietti  4 , M A Ponce  4 , E Longo  5
Affiliations

Synthesis and defect characterization of hybrid ceria nanostructures as a possible novel therapeutic material towards COVID-19 mitigation

L S R Rocha et al. Sci Rep. .

Abstract

This study reports the synthesis of hybrid nanostructures composed of cerium dioxide and microcrystalline cellulose prepared by the microwave-assisted hydrothermal route under distinct temperature and pH values. Their structural, morphological and spectroscopic behaviors were investigated by X-Rays Diffraction, Field Emission Gun Scanning Electron Microscopy, High-Resolution Transmission Electron Microscopy, and Fourier-Transform Infrared, Ultraviolet-Visible, Raman and Positron Annihilation Lifetime spectroscopies to evaluate the presence of structural defects and their correlation with the underlying mechanism regarding the biocide activity of the studied material. The samples showed mean crystallite sizes around 10 nm, characterizing the formation of quantum dots unevenly distributed along the cellulose surface with a certain agglomeration degree. The samples presented the characteristic Ce-O vibration close to 450 cm-1 and a second-order mode around 1050 cm-1, which is indicative of distribution of localized energetic levels originated from defective species, essential in the scavenging of reactive oxygen species. Positron spectroscopic studies showed first and second lifetime components ranging between 202-223 ps and 360-373 ps, respectively, revealing the presence of two distinct defective oxygen species, in addition to an increment in the concentration of Ce3+-oxygen vacancy associates as a function of temperature. Therefore, we have successfully synthesized hybrid nanoceria structures with potential multifunctional therapeutic properties to be further evaluated against the COVID-19.

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Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1
Figure 1
XRD patterns of the samples synthesized by microwave-assisted hydrothermal method at 100 and 120 °C with pH 10, 12 and 14.
Figure 2
Figure 2
SEM micrographs of the (a) raw microcrystalline cellulose and hybrid structures prepared with the MAH route at (b) 100 °C, pH 10, (c) 100 °C, pH 12, (d) 100 °C, pH 14, (e) 120 °C, pH 10, (f) 120 °C, pH12 and (g) 120 °C, pH 14.
Figure 2
Figure 2
SEM micrographs of the (a) raw microcrystalline cellulose and hybrid structures prepared with the MAH route at (b) 100 °C, pH 10, (c) 100 °C, pH 12, (d) 100 °C, pH 14, (e) 120 °C, pH 10, (f) 120 °C, pH12 and (g) 120 °C, pH 14.
Figure 3
Figure 3
TEM micrographs of samples prepared at 100 °C and 120 °C with pH 10 and 14, respectively.
Figure 3
Figure 3
TEM micrographs of samples prepared at 100 °C and 120 °C with pH 10 and 14, respectively.
Figure 4
Figure 4
UV–Vis spectra of the microcrystalline cellulose (upper) and the hybrid nanostructures composed of CeO2@MCC (lower).
Figure 5
Figure 5
FT-IR spectra of the as-synthesized particles and the raw microcrystalline cellulose.
Figure 6
Figure 6
Raman spectra of the hybrid structures and the MCC.
Figure 7
Figure 7
Schematic representation of the τ1 evolution as a function of reaction pH for the different synthesis temperatures. The corresponding lifetimes for the free-defect CeO2 and the Ce3+-oxygen vacancy associates are also presented.
See this image and copyright information in PMC

References

    1. Munster VJ, Koopmans M, van Doremalen N, van Riel D, de Wit E. A novel coronavirus emerging in China: Key questions for impact assessment. N. Engl. J. Med. 2020;382:692–694. - PubMed
    1. Rothan HA, Byrareddy SN. The epidemiology and pathogenesis of coronavirus disease (COVID-19) outbreak. J. Autoimmun. J. 2020;109:102433. - PMC - PubMed
    1. Sivasankarapillai VS, et al. On facing the SARS-cov-2 (COVID-19) with combination of nanomaterials and medicine: Possible strategies and first challenges. Nanomaterials. 2020;10:1–23. - PMC - PubMed
    1. Zinatloo-Ajabshir S, Morassaei MS, Amiri O, Salavati-Niasari M. Green synthesis of dysprosium stannate nanoparticles using Ficus carica extract as photocatalyst for the degradation of organic pollutants under visible irradiation. Ceram. Int. 2020;46:6095–6107.
    1. Etemadi H, Afsharkia S, Zinatloo-Ajabshir S, Shokri E. Effect of alumina nanoparticles on the antifouling properties of polycarbonate-polyurethane blend ultrafiltration membrane for water treatment. Polym. Eng. Sci. 2021;61:2364–2375.

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