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Journal of Biomedicine and Biotechnology
Volume 2007 (2007), Article ID 52971, 7 pages
http://dx.doi.org/10.1155/2007/52971
Research Article

Blue-Emitting Small Silica Particles Incorporating ZnSe-Based Nanocrystals Prepared by Reverse Micelle Method

Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Kansai Center, 1-8-31 Midorigaoka, Ikeda 563-8577, Osaka, Japan

Received 16 May 2007; Revised 17 December 2007; Accepted 24 December 2007

Academic Editor: Marek Osinski

Copyright © 2007 Masanori Ando et al. 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.

Abstract

ZnSe-based nanocrystals (ca. 4-5 nm in diameter) emitting in blue region (ca. 445 nm) were incorporated in spherical small silica particles (20–40 nm in diameter) by a reverse micelle method. During the preparation, alkaline solution was used to deposit the hydrolyzed alkoxide on the surface of nanocrystals. It was crucially important for this solution to include Zn2+ ions and surfactant molecules (thioglycolic acid) to preserve the spectral properties of the final silica particles. This is because these substances in the solution prevent the surface of nanocrystals from deterioration by dissolution during processing. The resultant silica particles have an emission efficiency of 16% with maintaining the photoluminescent spectral width and peak wavelength of the initial colloidal solution.