Volume 10, No. 2, June 2022
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Silica-Coating of Quantum Dots by Using Water Glass and Their Photo-Bleaching Properties

Akitoshi Tokumasu1, Tomoya Inose2, Noriko Yamauchi1, Chihiro Kato2, Kohsuke Gonda2,3, and Yoshio Kobayashi2
1.Department of Materials Science and Engineering, Graduate School of Science and Engineering, Ibaraki University, Japan.
2.Department of Medical Physics, Graduate School of Medicine, Tohoku University, Japan.
3.International Center for Synchrotron Radiation Innovation Smart (SRIS), Tohoku University, Japan.
Abstract: An uncomplicated, secure, and low environmental load method for suppressing the oxidation and aggregation of luminescent semiconductor nanoparticles like spherical nanoparticles comprising of cadmium compounds, or quantum dots (QD), is awaited to be developed. This paper expresses silica-coating of the QDs in water by means of a method using sodium silicate, and their fluorescence properties. The QDs were silica-coated by adding sodium silicate to the QDs with a size of 9.3±1.2 nm dispersed in water. A structure of the silica-coated QDs (QD/SiO2) was a core-shell type with the QDs as core and the silica as shells, and had a particle size of 28.6±2.7 nm. IVIS images with intensities larger than those of uncoated QDs were taken for the QD/SiO2. Although fluorescence intensity of the QD/SiO2 measured by a conventional fluorescence spectroscopy decreased with aging at room temperature in a dark box open to the atmosphere, the fluorescence intensity was stable after the drastic decrease in fluorescence intensity.

Key words: Quantum dot, Cadmium-related semiconductor, Core-shell, Silica-coating, Sol-gel, fluorescence.

Cite: Akitoshi Tokumasu, Tomoya Inose, Noriko Yamauchi, Chihiro Kato, Kohsuke Gonda, Yoshio Kobayashi, "Silica-Coating of Quantum Dots by Using Water Glass and Their Photo-Bleaching Properties," International Journal of Materials Science and Engineering, Vol. 10, No. 2, pp. 33-41, June 2022. doi: 10.17706/ijmse.2022.10.2.33-41
Copyright © 2022 by the authors. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).


General Information

ISSN: 2315-4527 (Print)
Abbreviated Title: Int. J. Mater. Sci. Eng.
Editor-in-Chief: Prof. Emeritus Dato' Dr. Muhammad Yahaya
DOI: 10.17706/ijmse
Abstracting/ Indexing: Ulrich's Periodicals Directory, Google Scholar, Crossref
E-mail: ijmse@iap.org