Photonic Crystal Fiber Plasmonic Biosensor for SARS-CoV-2 Particle Quantification and Detection

We conceptualized and analyzed a photonic crystal fiber (PCF) based plasmonic sensor to rapidly detect and quantify novel coronavirus. The performance of the proposed surface plasmon resonance (SPR) sensor, which has an analyte channel and gold wire, is carried out from three aspects for quantifying virus concentrations in the human body based on various ligand-analyte pairs. This biosensor can effectively detect SARS-CoV-2 spike receptor-binding-domain (RBD), human monoclonal antibody immunoglobulin G (IgG), and mutated viral single-stranded ribonucleic acid (RNA). Performance evaluation through finite element method (FEM)-based numerical analysis revealed maximum wavelength sensitivity (MWS) of 8333.33 nm/RIU for RNA detection, 6666.66 nm/RIU for spike protein detection, and 6145.44 nm/RIU for IgG quantification. Corresponding maximum amplitude sensitivity (MAS) was measured of 172.86 RIU^-1, 155.63 RIU^-1, and 156.38 RIU^-1, respectively. The sensor showed the most intense responses for viral RNA detection, achieving a high resolution of 1.20\(\times \)10^-05 RIU with a significantly low limit of detection (LOD) of 1.44\(\times \)10^-09 RIU²/nm. Hence, this proposed compact photonic sensor holds promise for rapid point-of-care COVID testing.