Biological immunoassay utilizing magnetoresistive sensor and magnetic-field-controlled binding between magnetic markers and targets

This research presents the development of a magnetic immunoassay technique using magnetic markers and magnetoresistive sensor for used in the liquid phase detection of biological targets. In this method, bound and free markers can be magnetically distinguished by using Brownian relaxation of magnetic markers, eliminating time consuming washing process for marker separation. Biotin molecules as targets and streptavidin-conjugated magnetic markers were used for detection.