Design and Analysis of High-Performance Optical Fiber-Based Surface Plasmon Resonance Sensor for Early Detection of Colorectal Cancer

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. Detecting colorectal cancerCRC at an early stage can help in saving lives and prevents cancer development. Also, it offers better treatment options, reduces mortality rates, and cost-effective. Therefore, this article presents design and analysis of an optical fiber-based surface plasmon resonance (SPR) sensor to detect CRC. In this work, we propose an optical fiber-based SPR sensor consisting of a structure of high-energy-peaked BL Lac (HBL) core-cladding-silver (Ag)–zinc oxide (ZnO)–tungsten disulfide (WS2) analyte, whereas Ag provides the sharp resonance dip, ZnO provides the protection from the Ag’s oxidation, and WS2 enhances the sensing capability. The sensor’s performance is analyzed by applying the wavelength interrogation technique. In this, first, the optimization of Ag, ZnO, and WS2 layers’ thicknesses, and incident angle is executed by observing the performance of minimum transmittance power, full-width at half-maximum (FWHM), and sensitivity. Second, the sensing parameters of limit of detection (LoD), detection accuracy (DA), sensitivity, and figure of merit (FoM) are analyzed with the help of optimized structure. Results show that the maximum achieved parameters are an LoD of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${2} \times {{10}}^{-{7}}~\text {RIU}$ </tex-math></inline-formula>, a DA of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${1.16} \times {{10}}^{-{3}}$ </tex-math></inline-formula>, a sensitivity of 7000 nm/RIU, and an FoM of 80 RIU-1. The results furnish a substantial improvement in comparison to the reported work in the literature.