Low index dielectric mediated surface plasmon resonance sensor based on graphene for near infrared measurements

Abstract

We numerically demonstrate and propose a low index dielectric (Teflon) mediated surface plasmon resonance (SPR) sensor based on graphene in a dielectric–metal–dielectric configuration, for near infrared measurements, by taking advantage of the high adsorption efficiency of graphene and the high-resolution resonance feature of low loss surface plasmons. The proposed configuration supports the low loss surface plasmon mode which is evident from its mode field distribution and effective index dispersion. Results show that at a wavelength of 850 nm, the field intensity enhancement factor at the graphene-sensing layer interface for the proposed chalcogenide Ge20Ga5Sb10S65 (2S2G)–Teflon–Au–graphene based sensor is 20% greater than for the 2S2G–Au–graphene based sensor, thereby increasing the imaging sensitivity by 50%. Moreover, for the proposed sensor, the penetration depth of the field into the sensing region is 340% greater than for the conventional (2S2G–Au–graphene) SPR sensor. The proposed SPR sensor could present new possibilities for SPR imaging and detection for highly sensitive and high-throughput assessment of multiple simultaneous molecular interactions.