Journal of Nanoparticle Research

, Volume 11, Issue 2, pp 441–448

Aqueous immune magnetite nanoparticles for immunoassay

  • Guoxin Zhang
  • Yanbo Liu
  • Chunfu Zhang
  • Weiqing Hu
  • Wanbang Xu
  • Zheng Li
  • Sheng Liang
  • Jinquan Cao
  • Yongxian Wang
Technology and Applications

DOI: 10.1007/s11051-008-9432-x

Cite this article as:
Zhang, G., Liu, Y., Zhang, C. et al. J Nanopart Res (2009) 11: 441. doi:10.1007/s11051-008-9432-x

Abstract

Immune magnetite nanoparticles (MNPs) are prepared by four successive reactions, which are MNPs preparation, silica-coating, surface modification with amino group, and conjugation with bio-molecule, respectively. The crystal structure and morphology of intermediate products are characterized by XRD, TEM and AFM. Qualitative and quantitative assays for amino group on the MNPs’ surface are made by FTIR and Organic Element Assay. Ultraviolet–visible absorption spectrum can indirectly illustrate the quantity of bio-molecule conjugated with MNPs. In addition, specific combination and nonspecific combination of immune MNPs are measured by commercial RIA box. The results show that the size of MNPs prepared is 10 ± 5 nm, and silica-coated MNPs with spinel structure have quasi-spherical morphology. Infrared absorption bands of –NH2 are appeared around 3380–3200 cm−1 and 1650–1510 cm−1, and the amino group content is 0.5 μmol –NH2 per mg MNPs. The specific immune combination of immune MNPs is up to 75%, and nonspecific combination is under 5%.

Keywords

Magnetite nanoparticles Silica-coating Surface modification Immunity Nanomedicine 

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • Guoxin Zhang
    • 1
  • Yanbo Liu
    • 2
  • Chunfu Zhang
    • 1
  • Weiqing Hu
    • 1
  • Wanbang Xu
    • 1
  • Zheng Li
    • 1
  • Sheng Liang
    • 1
  • Jinquan Cao
    • 1
  • Yongxian Wang
    • 1
  1. 1.Shanghai Institute of Applied PhysicsChinese Academy of SciencesShanghaiPeople’s Republic of China
  2. 2.Shanghai Nanotechnology Promotion CenterShanghaiPeople’s Republic of China