Depending on environmental conditions, polypeptide chains have a propensity to form highly stable, insoluble protein aggregates with a β-sheet rich structure, known as amyloid fibrils. These protein fibrils have increasingly been recognised as a potential bionanomaterial as they are highly stable, can self assemble allowing a bottom up approach to material design, have a high surface to volume ratio due to their nanometre size and can act as scaffolds for addition of functional groups via surface amino acid residues. Additionally, the use of amyloid fibrils formed from crude crystallin proteins in this area would add value to a low value by-product. These biological nanostructures are not toxic to cells, are mechanically and chemically stable, are resistant to organic solvents, can be easily functionalised and can be used in various biological and non-biological applications. This research is investigating the use of amyloid fibrils formed from different sources of proteins, such as bovine insulin, β-lactoglobulin and crystallin, as a versatile nanoscaffold.
The work to be presented regards the functionalisation of these amyloid fibrils with enzymes, such as glucose oxidase. By functionalisation with enzymes, amyloid fibrils can be used in various applications, such as glucose sensing. Glucose oxidase was covalently immobilised to the surface of fibrils, and deposition of these modified fibrils onto gold electrodes creates a functional glucose sensing device. Aside that many enzymes used in the food industry are quite expensive and suffer from serious drawback of poor stability and reusability. To encourage industrial applications of these enzymes; functionalising surface assembled amyloid fibrils utilising glass as a model surface resulting in stabilised biocatalyst is considered in this work. Successful immobilisation of these enzymes have several advantages, such as immobilised enzymes can be reused and can have improved stability. Future research intends to further explore the biosensing potential of amyloid fibrils, along with potential applications in other areas of nanoelectronics and to create bionanomaterials with enzymatic activity.