Magnetoimpedance biosensor for Fe3 O4 nanoparticle intracellular uptake evaluation

Abstract

Iron oxide (Fe3 O4) nonspecific nanoparticles of 30 nm are embedded inside human embryonic kidney (HEK 293) cells by intracellular uptake with a concentration of ∼ 105 particles/cell. An amorphous ribbon of Co64.5 Fe2.5 Cr3 Si15 B15 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. © 2007 American Institute of Physics.