Gold coated surface plasmon resonance based biosensor: An hexagonal photonic crystal Fiber platform

We numerically analyze a dual-core gold coated photonic crystal fiber (PCF) biosensor based on surface plasmon resonance that can be used for remote sensing applications in place of the traditional prism-based biosensor. Chemically stable active plasmonic material gold (Au) are positioned outside the fiber structure as a sensing layer to facilitate the construction of the sensor. From finite element method (FEM) based simulation, it is shown that the proposed sensor has the maximum wavelength sensitivity of 5000 nm/RIU. In addition, the amplitude sensitivity of the sensor is 267.66 RIU⁻¹ with the resolution of 2.00 × 10⁻⁵ RIU⁻¹ having sensing range of analyte refractive index 1.30 to 1.40. The suggested two-ring dual-core PCF sensor can be used to detect biological analytes, organic compounds, biomolecules, and other unidentified analytes due to its high sensitivity, enhanced sensing resolution, and suitable linearity properties. The proposed sensor has high sensitivity and wide operating range; from visible to mid-infrared which enables the detection of various biomolecules with different absorption or fluorescence spectra. Overall, the unique combination of structural design and optical properties make hexagonal PCF biosensor a promising and innovative platform for advanced and high-performance biosensing applications.