Plasmonic Fiberoptic Competitive Immunosensor: Proof-of-concept Studies

Small molecule detection is essential for various fields including clinical diagnostics, environmental monitoring, and drug discovery. Typically, a competitive assay is utilized due to the small size of the analyte, as opposed to a sensitive sandwich immunoassay format for their detection. Here, we demonstrate the highly sensitive plasmonic fiberoptic absorbance biosensor (P-FAB) for competitive assays with human IgG and gold nanoparticles (AuNP) as analyte and label, respectively. Numerical estimations for AuNP size and the proof-of-concept results are presented.