Imaging ellipsometry as a novel detection method for protein-protein interactions

Abstract

This thesis describes the use of a novel imaging ellipsometry system to detect protein-protein interactions (PPI) with an emphasis on antigen-antibody interaction (AAI) for potential use as a diagnostic technique. Consequently, a practical method for the detection of AAI using a bio-sensor based approach, imaged by the Aberystwyth Imaging Ellipsometer (AIE) is described. A case study bio-sensor was fabricated by the immobilization of an anti-Fasciola hepatica sigma class glutathione transferase (FhGST-S1) antibody and probed with analyte solutions derived from the zoonotic parasite F. hepatica. Specifically, incubation of biosensors with recombinant FhGST-S1 produced a detectable change in film thickness of 5.6(±0.91)nm in strong agreement with the protein size as described previously. Furthermore, analysis of the biosensor with F. hepatica extracellular vesicles (EV) also generated a detectable change in film thickness of 8.2(±1.02)nm. However, this observed change in thickness was less than that typically expected for EVs, which at a minimum are noted to be 10-50nm. Nevertheless, this approach has indicated the use of AAI in combination with a bio-sensor and AIE, for the potential diagnosis of F. hepatica infection. Given the early success documented throughout this work, this research highlights the AIE for detecting AAI in a non-contact, non-destructive and label free way. Specifically the use of the AIE has merit in its simplicity of operation and low cost, which holds the potential for further improvement and development for use in the diagnostics of infectious diseases

Date of Award	2019
Original language	English
Awarding Institution	Aberystwyth University
Supervisor	Russ Morphew (Supervisor) & Dave Langstaff (Supervisor)