Magnetoresistive Characteristics According To Size And Distribution Of Magnetic Particles For Antibody Conjugation In Between Cu Electrodes

For the development of antibody therapeutics, magnetoresistance (MR) characteristics according to the size and distribution of superparamagnetic magnetic beads (MBs) and magnetic nanoparticles (MNPs), each with surfaces functionalized by silanol and carboxyl groups with magnetite (Fe3O4) cores, were investigated. Particles of different sizes were placed within a 1 mm space in the center of a plastic tank that could contain up to 10 mu l in volume. A magnetic field was applied to the tank in order to distribute the particles. The minimum MR value, MR ratio, and solution coercivity obtained from the voltage curve, measured according to the strength of the external magnetic field passing through the MBs solution, were 3.567 M Omega, 1.1%, and 400 Oe, respectively; for the MNPs solution, 0.245 M Omega, 50%, and 184 Oe, respectively. The MNPs solution containing 0.35 Omega m sized particles showed a much more sensitive change in MR properties than the MB solution with 1 mu m sized particles. This phenomenon was analyzed to have been caused by the estimated split distance (ESD) created by the movement of different sized magnetic particles and whether a large or small number of estimated degree of solution pathway (EDSP) were created in response to an external magnetic field. It was discussed that these characteristics could potentially be used to control the function of various biomolecules, including antibodies conjugated to the surface of MNPs.