In recent years, research has been intensively carried out on the applicability of magnetic beads (MBs) and magnetic nanoparticles coupled to biological objects such as red blood cells (RBCs). The magnetoresistance (MR) of a solution of RBCs and MBs (RBCs+MBs) was evaluated when MBs migrated in the presence or absence of an external magnetic field. The pattern of distribution of the MBs, which were homogeneously suspended in deionized distilled water, varied depending on the magnitude of the external magnetic field applied between the Cu electrodes connected to the two terminals. As the magnitude of the external magnetic field is increased or decreased, MBs are split on both sides and evenly mixed, respectively. The ratios (ΔMR/MR) versus an external magnetic field for the solutions of only MBs and a mixed RBCs+MBs were -33.4% and -27.4% at ±30 Oe and ±46 Oe of coercive fields, respectively. These results show that a solution of RBCs+MBs can act like a high-resolution biosensor that detects the oxygenation state of RBCs.
Keywords: Deionized distilled water (ddH2O); Magnetic bead (MB); Magnetoresistance (MR) curve; Red blood cell combined with magnetic beads (RBC+MBs).