Propagating and Localised Plasmonic and Magneto-Plasmonic Transductors for Gas and Biosensing Applications

Abstract

Surface Plasmon Resonance (SPR) is known as a leading technology for label-free biosensing. It is based on the optical detection of refractive index changes occurring at a metal/dielectric interface upon a proper choice of the metal layer, its thickness as well as on the excitation light beam. Biological and chemical analysis are achieved by functionalizing the gold surface with surface bioreceptors and measuring the shift of corresponding optical signals when a biomolecular reaction occurs. In order to increase the sensing performances two strategies have been adopted: a proper combination of noble metal and ferromagnetic materials tailored on the nanoscale is used as novel transducer in SPR-based biosensor coupled with an external magnetic field; and a new 3D transductor consisting of silica nanowires decorated by gold nanoparticles have been realized to increase the performance of sensing devices In both case increasing biosensing performance have been demonstrated.