A theoretical analysis to improve the tuning and sensitivity of a surface plasmon resonance biosensor employing titanium disilicide-graphene heterostructures

A surface plasmon resonance-based biosensor is investigated theoretically and mathematically. The proposed sensor is a multilayered structure of titanium disilicide and graphene along with Ag metal. These layers are stacked over a BK7 prism. The thickness of the metal, titanium disilicide, and graphene layers is 45 nm, 2 nm, and 1.7 nm, respectively. Titanium disilicide is an air-stable two-dimensional (2D) material. The performance of the biosensor is analyzed using the attenuated total reflection (ATR) method. The proposed configuration exhibits a maximum sensitivity of 183.4 degrees/RIU, being 47.45% higher than that of the conventional sensor. The designed sensor has wide applications in chemical, medical, and biological analyte sensing.