Enhanced sensitivity of SPR biological sensor based on nanohole arrays in gold films

In this paper, we demonstrate that the nature of surface plasmons in nano-structured gold films - with arrays of nanoholes - is significantly affected by variation in the period and the diameter of these nanoholes. These nanohole arrays in gold films can be employed for real-time sensing applications with enhanced sensitivity. In this paper, numerical simulations using rigorous coupled wave analysis (RCWA) are carried out to study the effect of different periods and diameters of the nanoholes on the angulo-spectral reflectance maps. These maps are analyzed in detail to study the dependence of surface plasmon behaviour on the geometrical parameters in these structures, and enhanced sensitivity is demonstrated for localized refractive index sensing.