Liquid-phase detection of biomaterial using magnetic markers

Yoshitsugu Takafuji, Kohta Irie, Takashi Yoshida, Keiji Enpuku

Research output: Contribution to journalArticlepeer-review


We have been developing a liquid-phase immunoassay using magnetic markers and a superconducting quantum interference device (SQUID). In this method, bound and free markers are magnetically differentiated by using the Brownian relaxation of the free markers. Hence, the time consuming washing process that is needed in the conventional optical method for Bound/Free (B/F) separation can be eliminated. Using the method, we demonstrated a detection of C-reactive protein (CRP). We obtained good correlation between the detected signal flux and the concentration of CRP. The minimum detectable concentration was 1 pg/mL. Since the present sensitivity is limited by the blank signal caused by the aggregation of free markers, much improvement will be possible if this problem is solved.

Original languageEnglish
Pages (from-to)1-7
Number of pages7
JournalResearch Reports on Information Science and Electrical Engineering of Kyushu University
Issue number1
Publication statusPublished - Jan 2018

All Science Journal Classification (ASJC) codes

  • General Computer Science
  • Electrical and Electronic Engineering


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