Highly Sensitive Dual-Channel PCF Based SPR Biosensor for Multi-Analyte Detection with Fabrication Tolerance Analysis

This research introduces an exceptionally sensitive PCF-SPR sensor with multiple channels, designed for detecting multiple analytes simultaneously. Numerical simulations, performed through the finite element method (FEM), were used to evaluate the sensor’s performance. The proposed design incorporates two different plasmonic materials: $\mathrm{Ch}-1$ uses a combination of Gold (Au) and Tantalum Pentoxide (Ta<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</inf>), whereas $\mathrm{Ch}-2$ relies solely on Gold (Au). Demonstrating exceptional sensitivity spanning refractive index (RI) changes from 1.33 to 1.38 and 1.33 to 1.41, it achieves maximum wavelength sensitivities of 83,000 $\mathrm{nm} /$ RIU for Ch-1 and $22,000 \mathrm{~nm} /$ RIU for Ch-2. Additionally, it exhibits remarkable maximum amplitude sensitivities of 1167.9 RIU $^{-1}$ and 909.1 RIU $^{-1}$ for Ch-1 and Ch-2, respectively, alongside a minimum sensor resolution of $1.2 \times 10^{-6}$ RIU. The sensor sets a new standard with a figure of merit (FOM) of $2371 \mathrm{RIU}^{-1}$, outperforming previously documented multichannel sensors. It addresses existing limitations by offering greater sensitivity, enhanced detection precision, easier fabrication, a higher FOM, and improved resolution. We anticipate that this sensor will be effectively utilized to detect a wide array of substances, including chemicals, organic and inorganic compounds, medical diagnostics, food safety, and biochemical research.