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Abstract
Bacteriophages have emerged as a tool for functional material development, such as bacterial sensors, capture systems and antimicrobial surfaces. The fabrication and application of bacteriophage based interfaces however still remain a challenge due to the lack of understanding in the mechanism of virus-surface interactions and the contribution of such interactions to the end-point applications. This thesis reports the use of controlled surface modification for the adsorption of bacteriophage with the ultimate aim of being able to better understand the mechanism and critical factors involved in virus-surface interactions, as well as the influence of such interactions to the end-point applications.
The work starts with the control surface modification of planar indium tin oxide (ITO) as a model substrate for T4 bacteriophage adsorption to establish the mechanism and surface physico-chemical properties involved in the virus-surface interactions. The T4 bacteriophage adsorption to planar and particulate ITO suggest the significance of substrate physical configuration to the adsorption of bacteriophage. The importance of surface chemical properties is also reflected on the adsorption of T4 onto bare, -NH2 and -COOH functionalised planar ITO.
The second part of the thesis focuses on the use of bacteriophage conjugated magnetic particles (Fe3O4) for the rapid capturing and isolation of Escherichia coli. It was revealed for the first time that a successful bacteria capturing requires not only an optimum tailoring of the particle’s surface physicochemical properties for high bacteriophage loading, but also an in-depth understanding of how external factors, such as temperature and solution chemistry influence the subsequent bacteriophage-bacteria interactions.
The last part of the thesis explores the antimicrobial activity of bare and functionalised ITO conjugated with T4 bacteriophage to E. coli. The variation in bacteriophage loading appears to have minimum influence to the antimicrobial activity, which reveals the paramount importance of understanding the mechanism of action of the end-point applications as it provides an insight into factors that count to such activity. The presence of food components, such as casein and starch did not interfere with the antimicrobial activity of ITO/T4, meanwhile the variations in solution pH, specifically at pH 5 was found to significantly impede the antimicrobial activity of ITO/T4.