Sensitivity Enhancement of Franckeite-Based Surface Plasmon Resonance Sensors Using A Bimetallic Structure

This study proposes the franckeite layer onto a bimetallic (Au–Cu) based sensor. The proposed sensors use CaF₂ prism, Au (39 nm), Cu (5 nm), with/without franckeite, and adsorption layer (sensing medium (SM). All the performance analysis is carried out at 633 nm wavelength. At optimized, the bimetallic layer, the remarkable sensitivity, DA, and FoM of 350.76°/RIU, 0.144/°, and 50.50/RIU are achieved, respectively. The proposed sensor’s computed electric field (EF) intensity and penetration depth (PD) are 2.11 × 105 V/m and 204.28 nm at an RI of 1.330 SM. With a quick response indicated by a significant shift in resonance angle, the suggested structure would help detect the RI between 1.33 and 1.335. A detailed comparison with the most recent publications in biomedical applications confirms the outstanding performance of the proposed SPR sensors. This comparison highlights the significant potential of the sensors in biosensing and biomedicine.