Immunomagnetic reduction assay using high-Tc superconducting-quantum-interference-device-based magnetosusceptometry

Via immunomagnetic reduction assay, biomolecules can be quantitatively detected with aid of biofunctionalized magnetic nanoparticles, which are used as labeling markers for specific biomolecules. To achieve ultra-high sensitivity in detecting biomolecules, superconducting quantum interference device (SQUID) is a promising candidate to act as a sensor to the magnetic signal related to the concentration of detected biomolecules. In the past, we developed a single channel SQUID-based magnetosusceptometry. In order to increase the detection through-put, multichannel SQUID-based magnetosusceptometry is developed. In this work, the design and working principle of four-channel SQUID-based magnetosusceptometry are introduced. Using utilizing scanning technology, four samples can be simultaneously logged into the SQUID-based magnetosusceptometry. Notably, only single SQUID magnetometer is used in the magnetosusceptometry. The precision and sensitivity in detecting biomolecules using the four-channel SQUID-based magnetosusceptometry are investigated. (C) 2010 American Institute of Physics. [doi:10.1063/1.3340861]