Enhanced sensitivity of a surface plasmon resonance biosensor utilizing Au/ITO hyperbolic metamaterial

A surface plasmon resonance (SPR) sensor unitizing hyperbolic metamaterial (HMM) composing by a few pairs of Au and ITO layers was proposed. The sensing performance of Au/ITO-HMM sensor was demonstrated to be tuned by the metal filling fraction and the incidence angle of light by simulation. Electric field and penetration depth distributions at the sensing interface were calculated to explain the physical mechanism of sensitivity enhancement. With the light incident angle of 75 degrees and 66 degrees, we experimentally demonstrated that the proposed SPR sensor could achieve the average sensitivity of 3341 nm/RIU and 14242 nm/RIU, respectively. The proposed Au/ITO-HMM-SPR sensor with ultra-high sensitivity can be found potential application in the biochemical sensing with much lowered concentration.