Numerical Analysis of Hybrid - SPR-PCF Multi-Analyte Sensor for Clinical Diagnosis

In this article, we numerically demonstrate the label-free surface plasmon resonance-based multi-analyte hybrid photonic crystal fiber sensor (SPR-PCF), which can sense broad refractive index (RI) ranges from 1.34 to 1.51, respectively. The three thin plasmonic metal nanocaps are deposited on the top and bottom layers of the magnesium fluoride MgF2 nanopillars. The silver (Ag) and gold (AU) caps in both channels (internal and external) activate the sensor’s plasmon resonance condition. The magnesium fluoride (MgF2) nanopillar improves the binding process of metal nanocaps and liquid analytes. The finite element method (FEM)-based comsol multiphysics tool is used for numerical analysis of the proposed design. This numerical investigation exhibits maximum wavelength sensitivity (10,000 nm/RIU, 15,000 nm/RIU), minimum confinement losses (0.78 dB/cm, 0.0015 dB/cm), and high resolutions (6.66 × 10⁻⁶) for multi-analytes refractive index samples from RI 1.33 to 1.51. Due to high sensitivity, low confinement losses, and multi-analyte sensing capabilities, the proposed sensor applies to detect unknown analytes in clinical diagnosis for health care applications.