Evaluation of thermo responsive magnetic nano-particles for high-Tc SQUID bio application

S. Tanaka*, C. Toriyabe, Y. Torii, Y. Hatsukade, T. Eki, S. Katsura, N. Ohnishi, J. Wan, S. Yang, Y. Zhang

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


Immunoassay or detection of biological molecules using a high sensitive SQUID and magnetic nano-particles as labeling has been recently proposed. In this method, mostly a few particles are labeled on an antibody or biological molecules. If it is possible to give much more magnetic particles to the antibody, sensitivity must notably increase. We propose the use of thermo responsive magnetic nano-particles, which can agglutinate and disperse by themselves associated with temperature. As a preliminary experiment, we investigated the properties of thermo responsive nano-particles made of Fe3O4. By detailed study on the particles using an analyzer for a distribution of particle's outer dimension in aqueous liquid, it was found that the dimension increased with temperature above 25°, and became 400 nm at 30.5°. Magnetic measurements of the particles at different conditions using high-Tc SQUID have been done. The results suggested that the particles must be dried by heat before magnetic measurement to enhance the signal from the particles.

Original languageEnglish
Pages (from-to)1029-1033
Number of pages5
JournalPhysica C: Superconductivity and its applications
Issue numberSUPPL.
Publication statusPublished - 2007 Oct 1
Externally publishedYes


  • FeO
  • Immunoassay
  • Particle

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering


Dive into the research topics of 'Evaluation of thermo responsive magnetic nano-particles for high-Tc SQUID bio application'. Together they form a unique fingerprint.

Cite this