two-dimensional ptse2 theoretically enhanced goos-hänchen shift sensitive plasmonic biosensors

Platinum diselenide (ptse2), an emerging two-dimensional transition metal dichalcogenide, exhibits thickness-dependent refractive index, and hence, intriguing optical properties. here, we employ it as a plasmonic sensing substrate to achieve significant enhancement in goos-hänchen shift sensitivity. through systematic optimization of all parameters, four optimum sensing configurations have been achieved at different wavelengths ranging from visible to near-infrared region, where the goos-hänchen shift sensitivity receives four times enhancement in comparison with the conventional bare gold sensing substrate. there is a linear range of goos-hänchen shift with the tiny change of refractive index for each optimal configuration. the detection limit of the refractive index change can be as low as 5 × 10−7 riu which is estimated to be lower by 2 orders of magnitude, and the corresponding sensitivity of biomolecules has a 1000-fold increment compared with that of bare gold-based sensors.