A Circular Shaped SPR PCF Biosensor Based on External Sensing Mechanism

This study introduces a circular shaped Photonic Crystal Fiber (PCF) employing Surface Plasmon Resonance (SPR) and featuring an open-channel arrangement, expanding its refractive index (RI) detection span from 1.34 to 1.44. Computational simulations employing the Finite Element Method (FEM) alongside perfectly matched layer (PML) boundary conditions elucidate the superior performance of the proposed SPR-PCF. Key metrics include a broad wavelength sensitivity of 27,000 nm/RIU, a notable amplitude sensitivity of 2944.94 RIU<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup>, and an impressive resolution of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{3.70}\times \mathbf{10}^{-\mathbf{06}}$</tex> RIU, underscoring its precision in biochemical sensing applications. Moreover, boasting a figure of merit (FOM) of 692 RIU<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup>, the SPR based PCF exhibits exceptional sensing capabilities. The incorporation of an open-channel architecture facilitates external sensing modalities, enhancing accessibility and affordability while ensuring a straightforward fabrication process.