Biomolecule-nanosheet assemblies

Abstract

The overall aim was to develop and exploit novel nanosheet-based biomolecule assemblies and arrays by immobilising proteins, directly and non-covalently, on 2D materials such as graphene. The biofunctionalized graphene could be tailored for potential use in electronic devices such as biosensors and smart materials. Due to its excellent material properties, graphene was programmed using various constructs of the amphipathic hydrophobin BslA from B. subtilis. BslA has a graphene-compatible hydrophobic face and an aqueous solvent-compatible hydrophilic face and therefore could act as an anchor to a non-native bioreceptor on the surface of graphene. Fluorescent proteins and epitopes (Ro52200-239, Ro60273-289 and HisRS1-60) for autoimmune antibodies were selected as interesting, detectable and purposeful modifications to BslA’s C-terminus via sortase-mediated ligation or recombinant fusion. For this reason, more than ten different BslA constructs were cloned, expressed and purified, to determine the optimal anchor sequence for enzyme and surface interactions. Sortase A was expressed and purified along with adapted mCherry and eGFP proteins for ligation reactions to BslA. Mono/few layers CVD graphene were isolated as the transducer for sensing. BslA adsorption on hydrophobic surfaces like graphene was studied using various techniques and experiments. A proof-in-concept label-free graphene-based biosensor for anti-HARS autoimmune antibody detection was designed and tested.

Date of Award	2 Oct 2024
Original language	English
Awarding Institution	University of Bath
Supervisor	Stefan Bagby (Supervisor)