Liquid-phase detection of biological targets with magnetic markers and high Tc SQUID

S. Uchida, Y. Higuchi, Y. Ueoka, T. Yoshida, K. Enpuku, S. Adachi, K. Tanabe, A. Tsukamoto

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

We developed a highly sensitive HTS SQUID system for liquid-phase detection of biological targets using Brownian relaxation of magnetic markers. The SQUID was made of a ramp-edge Josephson junction using RE123-based multilayer process, and it showed a flux noise of 7.5 micro flux-quantam/Hz1/2 in the white noise region. The 1/f noise was 14 micro flux-quantam/Hz1/2 at f = 1 Hz when the SQUID was operated with AC bias mode. Using the SQUID system, we detected a biological target called biotin. In the experiment, biotins were fixed to a large polymer bead with a diameter of 3.3 micron meter. Streptavidin-coated magnetic markers were used for the detection. The bound and unbound (free) markers were magnetically distinguished using the difference in their Brownian relaxation time, i.e., without using the washing process to separate them. The minimum detectable number of biotins was as low as 10 4, corresponding to a sensitivity of 4.8×10-19 mol/ml. This result indicates a high sensitivity of the developed method.

Original languageEnglish
Title of host publication2013 IEEE 14th InternationalSuperconductive Electronics Conference, ISEC 2013
DOIs
Publication statusPublished - Oct 15 2013
Event2013 IEEE 14th InternationalSuperconductive Electronics Conference, ISEC 2013 - Cambridge, MA, United States
Duration: Jul 7 2013Jul 11 2013

Publication series

Name2013 IEEE 14th InternationalSuperconductive Electronics Conference, ISEC 2013

Other

Other2013 IEEE 14th InternationalSuperconductive Electronics Conference, ISEC 2013
CountryUnited States
CityCambridge, MA
Period7/7/137/11/13

All Science Journal Classification (ASJC) codes

  • Electrical and Electronic Engineering

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