Magnetoimpedance biosensor for Fe3O4 nanoparticle intracellular uptake evaluation

Abstract
Iron oxide (Fe3O4) nonspecific nanoparticles of 30nm are embedded inside human embryonic kidney (HEK 293) cells by intracellular uptake with a concentration of ∼105 particles/cell. An amorphous ribbon of Co64.5Fe2.5Cr3Si15B15 exhibiting large magnetoimpedance (MI) serves as the sensing element. The presence of fringing fields of the nanoparticles changes the superposition of the constant applied field and the alternating field created by a current flowing through the ribbon that can be detected as a change in MI. This response is clearly dependent on the presence of the magnetic nanoparticles inside the cells and on the value of the external field.