Chemical modifications of graphene for biotechnology applications

Abstract

The aim of this thesis is to investigate different functionalization strategy of graphenenanomaterials for graphene-based different biotechnological applications such asgraphene-directed stem cell growth and differentiation and graphene-based biosensors.Chemical functionalization of graphene is required in many biological applications; inthis thesis we have focused on exploiting the carboxylic groups available on GOmolecules and non-covalent functionalization of graphene.GO has been a promising material for stem cell culture due to high specific surface area,ease of functionalization, its ability to support cell proliferation and to not causecytotoxicity when stem cells are cultured on its substrate. The impact of biochemicalfunctionalization on stem cell differentiation was not widely research, and many researchgroups worldwide have been focusing only on GO and rGO surfaces only. The approachof this thesis is to fabricate and characterize different graphene-based substrates toinvestigate the impact of biochemical functionalization of GO in directing adipose stemcell differentiation and to influence the gene expression pathways of Schwann-likedifferentiated adipose stem cells.The fabrication of graphene based biosensors is still challenging as biological moleculesneed to be attached to graphene-based sensors to increase both the specificity and theselectivity of the biosensors.In this thesis, two different chemical functionalization approaches were considered.Firstly, the covalent immobilization of membrane proteins embedded on a lipid nanodiscstructure on GO was achieved. Secondly, the feasibility of using dip-pen nanolithographyas a tool to locally functionalize graphene arrays with phospholipids was demonstrated.Phospholipid interface layer can act as bioactive layer which can be used for the proteininsertion of tail-anchoring recombinant proteins as a new route for a non-covalentbiological functionalization of graphene array.

Date of Award	1 Aug 2017
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Aravind Vijayaraghavan (Supervisor), Simon Webb (Supervisor) & Stephen High (Supervisor)