▎ 摘　　要

In this theoretical work, we have investigated the nature of reflectance from a graphene based SPR biosensor. Metals like gold, silver and copper are examined according to their minimum reflectance. The thickness of metal and graphene layers has been optimized to explore how plasmon dip varies with respect to number of graphene layers. It is found that plasmon dip does not vary linearly with respect to the number of graphene layers. However, by method of best fit, it is observed that plasmon dip varies as a three parameter exponential manner with the number of graphene layers. In addition, it is also shown that the shift of plasmon dip can be controlled by decreasing the thickness of metal (silver particularly) with increasing graphene layer.