Biological Immunoassay with High Tc Superconducting Quantum Interference Device (SQUID) Magnetometer(Special Issue on Superconductive Electronics)

概要

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A high Tc superconducting quantum interference device (SQUID) magnetometer system is developed for the application to biological immunoassay. In this application, magnetic nanoparticles are used as magnetic markers to perform immunoassay, i.e., to detect binding reaction between an antigen and its antiboby. The antibody is labeled with _r-Fe_2O_3 nanoparticles, and the binding reaction can be magnetically detected by measuring the magnetic field from the nanoparticles. Design and set up of the system is described, and the sensitivity of the system is studied in terms of detectable number of the magnetic markers. At present, we can detect 4 x 10^6 markers when the diameter of the marker is 50nm. Total weight of the magnetic nanoparticles becomes 520pg in this case. An experiment is also conducted to measure antigen-antibody reachtion with the present system. It is shown that the sensitivity of the present system is 10 times better than that of the conventional method using an optical marker. A one order of magnitude improvement of sensitivity will be realized by the sophistication of the present system.
社団法人電子情報通信学会の論文
2001-01-01