Fabrication of quantum dot/silica core–shell particles immobilizing Au nanoparticles and their dual imaging functions

Yoshio Kobayashi, Hiromu Matsudo, Ting ting Li, Kyosuke Shibuya, Yohsuke Kubota, Takahiro Oikawa, Tomohiko Nakagawa, Kohsuke Gonda

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

The present work proposes preparation methods for quantum dot/silica (QD/SiO2) core–shell particles that immobilize Au nanoparticles (QD/SiO2/Au). A colloid solution of QD/SiO2 core–shell particles with an average size of 47.0 ± 6.1 nm was prepared by a sol–gel reaction of tetraethyl orthosilicate in the presence of the QDs with an average size of 10.3 ± 2.1 nm. A colloid solution of Au nanoparticles with an average size of 17.9 ± 1.3 nm was prepared by reducing Au3+ ions with sodium citrate in water at 80 °C. Introduction of amino groups to QD/SiO2 particle surfaces was performed using (3-aminopropyl)-triethoxysilane (QD/SiO2-NH2). The QD/SiO2/Au particles were fabricated by mixing the Au particle colloid solution and the QD/SiO2-NH2 particle colloid solution. Values of radiant efficiency and computed tomography for the QD/SiO2/Au particle colloid solution were 2.23 × 107 (p/s/cm2/sr)/(μW/cm2) at a QD concentration of 8 × 10−7 M and 1180 ± 314 Hounsfield units and an Au concentration of 5.4 × 10−2 M. The QD/SiO2/Au particle colloid solution was injected into a mouse chest wall. Fluorescence emitted from the colloid solution could be detected on the skin covering the chest wall. The colloid solution could also be X-ray-imaged in the chest wall. Consequently, the QD/SiO2/Au particle colloid solution was found to have dual functions, i.e., fluorescence emission and X-ray absorption in vivo, which makes the colloid solution suitable to function as a contrast agent for dual imaging processes.

Original languageEnglish
Pages (from-to)301-307
Number of pages7
JournalApplied Nanoscience (Switzerland)
Volume6
Issue number3
DOIs
Publication statusPublished - 2016 Mar 1

Keywords

  • Au
  • Core–shell
  • Fluorescence imaging
  • Nanoparticle
  • Quantum dot
  • Silica coating
  • X-ray imaging

ASJC Scopus subject areas

  • Biotechnology
  • Atomic and Molecular Physics, and Optics
  • Materials Science (miscellaneous)
  • Physical and Theoretical Chemistry
  • Cell Biology
  • Electrical and Electronic Engineering

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