Self‐Referenced Guided Mode Resonance Biosensor Using 1D Titanium Dioxide Sub‐Wavelength Grating

ABSTRACT

A self‐referenced, highly sensitive one‐dimensional (1D) dielectric grating‐based optical sensor configured in the Kretschmann arrangement is proposed for biosensing applications. Numerical investigations using the finite element method (FEM) reveal that incorporating a titanium dioxide () grating onto a dielectric substrate substantially enhances sensing performance by exciting guided‐mode resonance at the waveguide–grating–external sensing medium interface. A comprehensive parametric study is carried out to systematically evaluate the influence of key structural parameters on the device's sensing characteristics. The proposed biosensor exhibits sensitivity values ranging from 714.28 nm/RIU to 1428.57 nm/RIU for different refractive index values corresponding to typical biological and cellular media (1.35 to 1.39), along with a detection resolution of  RIU. These performance metrics indicate a marked improvement over conventional grating‐based biosensors reported previously. Overall, the findings highlight the strong potential of the proposed platform for advanced biochemical and clinical sensing applications.