Biosensing Performance of Surface Plasmon Polariton Bragg Gratings

Abstract

Surface plasmon biosensors have raised much interest over the past few decades for their potential in biosensing applications. This thesis investigates the plasmon-polariton Bragg grating, which is a novel structure that supports surface plasmon modes. Plasmon-polariton Bragg gratings PPBGs consist of metal stripes embedded in Cytop. A number of designs were investigated to evaluate the biosensing capabilities of the device. The biosensing performance was studied for both bulk and surface sensitivities via wavelength interrogation. The biosensing study was conducted by observing changes in the effective refractive indices of the supported modes by changing the index of the sensing solution for bulk sensitivity, and by changing the thickness of the adlayer that represents the binding of the target analyte to the sensing surface for surface sensitivity. A theoretical assessment of the achievable sensitivity and detection limit for PPBGs is conducted via two approaches, wavelength and output power interrogation.