Surface Plasmon Resonance Biosensor Based on Hexagonally Structured Photonic Crystal Fibre

This study proposes a unique surface plasmon resonance (SPR) sensor utilizing a hexagonally structured photonic crystal fibre (PCF), able to identify a broad range of biological and biochemical analytes such as human intestinal mucosa, liver, cornea, and glucose solutions. The sensor’s performance is evaluated by applying the finite element method, with a gold layer chosen as the plasmonic metal for its durability and practicality. By analyzing the resonance wavelength shift due to different refractive indices of the analyte, the sensor demonstrates high sensitivity, resolution, and amplitude sensitivity. Specifically, the biosensor achieves a maximum wavelength sensitivity of 9000 nm/RIU, an amplitude sensitivity of $\mathbf{- 7 4 1 . 5 5} \mathrm{RIU}^{-1}$, and a resolution of $\mathbf{1 . 3 3} \times 10^{-5}$ RIU within the refractive index range of 1.31 to 1.38 for the unknown analyte (where RIU stands for Refractive Index Unit). The straightforward and practical hexagonal lattice structure of the biosensor simplifies the fabrication process, making it less complex. Additionally, this sensor has the potential to be utilized in accurately detecting 25% sugar solution and cornea (human). Consequently, the biosensor holds promise for various advanced diagnostic and analytical applications.