Date of Award

2021

Document Type

Master Thesis

Degree Name

Masters of Science (Research)

Department

Biological and Pharmaceutical Sciences

First Advisor

Dr. Joanna B. Tierney

Second Advisor

Dr. Niall Burke

Third Advisor

Dr. Daniela Iacopino

Abstract

Laser-scribed graphene electrodes (LSGE) are a low cost, portable, flexible and ideal electrochemical platform approach as point of care biosensors. It is anticipated that integrating the detection of immune cell inflammatory cytokines with LSGEs may present a useful diagnostic platform for managing the risk of inflammatory diseases as early detection of inflammatory molecules could significantly improve the treatment and outcome of diseases induced by protracted inflammation, such as cancer, asthma and rheumatoid arthritis. This study proposed LSGE first time novel use in the detection of an inflammatory cytokine released by immune cells (monocyte THP-1 cell line), with high sensitivity and short response time compared to conventional detection techniques like ELISA. Monocyte THP-1 cells were differentiated in to macrophages using phorbol 12-myristate 13-acetate and polarised into classically activated macrophages (M1), responsible for pro-inflammatory responses, with interferon-gamma (IFN-γ) and lipopolysaccharide (LPS). THP-1 macrophages were additionally polarised into alternatively activated macrophages (M2), responsible for anti-inflammatory responses, with interleukin4 (IL-4) and interleukin-13 (IL-13). To confirm inflamed cell states, cytokine and surface marker expression were assessed by ELISA and flow cytometry respectively. It was confirmed that M1 macrophage phenotype secreted the inflammatory cytokine IL-6 and expressed CD80 surface marker. M2 macrophage phenotypes secreted fibronectin and expressed mannose receptor CD206. IL-6 antigen was biofunctionalised onto the LSGE as the bioreceptor to enable the biosensor to detect IL-6 antibody. The LSGE was functionalised with 1pyrenebutyric acid (PBA) and EDC/NHS to create a linker that immobilisedation the bioreceptor, IL-6 antigen onto the surface of LSGE. The linear detection range of the LSGE biosensor was from 10 pg/mL to 500 pg/mL in physiological buffer solutions with interfering agents such as serum albumin showing no effect on biosensor detection abiltity.

Access Level

info:eu-repo/semantics/openAccess

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