Magneto-plasmonic films for biosensing applications

In this work a proper combination of metal and ferromagnetic multilayers tailored on the nanoscale is used as novel transducer in propagating SPR-based biosensor coupled with an external magnetic field. The modulation of plasmon moment by an external magnetic field has been demonstrated in literature . The coupling between the incident light and the surface plasma waves is determined by the magneto-optical (MO) properties of the magnetic layer that can be modulated using an external magnetic field. Moreover, such a combination of materials can produce a great enhancement of the MO effects when the Plasmon resonant condition is satisfied. The MO enhancement is strongly localized in the plasmon resonance conditions and critically depends on the refractive index of the dielectric medium. As a consequence, small variations of the refractive index will induce large changes in the MO response, allowing using the proposed platform as novel transducer for optical sensing .