Journal of Sol-Gel Science and Technology

, Volume 78, Issue 1, pp 82–90

Preparation of high-concentration colloidal solution of silica-coated gold nanoparticles and their application to X-ray imaging

  • Yoshio Kobayashi
  • Kyosuke Shibuya
  • Masayuki Tokunaga
  • Yohsuke Kubota
  • Takahiro Oikawa
  • Kohsuke Gonda
Original Paper: Nano-structured materials (particles, fibers, colloids, composites, etc.)

DOI: 10.1007/s10971-015-3921-z

Cite this article as:
Kobayashi, Y., Shibuya, K., Tokunaga, M. et al. J Sol-Gel Sci Technol (2016) 78: 82. doi:10.1007/s10971-015-3921-z

Abstract

This study proposes a method for preparing high-concentration silica-coated Au (Au/SiO2) nanoparticles in colloidal solution from 1.5 × 10−3 M hydrogen tetrachloroaurate (III) trihydrate as the Au source and 1.0 × 10−2 M sodium citrate as the reducing reagent. The colloidal solution is applied to X-ray computed tomography (CT) imaging of mouse tissue. The Au nanoparticles in the colloidal solution had a diameter of 18.9 nm, and the Au concentration reached 1.5 × 10−3 M. The Au nanoparticles were silica-coated by modifying their surfaces with (3-aminopropyl)trimethoxysilane (APMS), then depositing silica nuclei generated by a sol–gel reaction of tetraethyl orthosilicate (TEOS) in water/ethanol initiated with sodium hydroxide (NaOH) on the surface modified with APMS. A colloidal solution of Au/SiO2 core–shell particles (silica shell thickness = 19.7 nm) was formed in a final as-prepared solution of 2.7 × 10−4 M Au, 2.0 × 10−5 M APMS, 24 M H2O, 1.9 × 10−3 M NaOH, and 4.1 × 10−3 M TEOS. The Au in the as-prepared colloidal solution was further concentrated to 0.27 M by salting-out and centrifugation. The CT value of the concentrated Au/SiO2 colloidal solution was 2.52 × 103 Hounsfield units, double that of a commercial X-ray contrast agent with the same I concentration as the Au concentration. When injected into mouse tissue, the Au/SiO2 colloidal solution demonstrated good imaging capability.

Graphical Abstract

Keywords

Au Silica Core–shell Nanoparticle X-ray contrast agent 

Funding information

Funder NameGrant NumberFunding Note
Japan Society for the Promotion of Science
  • 24310085

Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • Yoshio Kobayashi
    • 1
  • Kyosuke Shibuya
    • 1
  • Masayuki Tokunaga
    • 2
  • Yohsuke Kubota
    • 2
  • Takahiro Oikawa
    • 2
  • Kohsuke Gonda
    • 2
  1. 1.Department of Biomolecular Functional Engineering, College of EngineeringIbaraki UniversityHitachiJapan
  2. 2.Graduate School of MedicineTohoku UniversitySendaiJapan

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