Protein Stabilising Molecular Gels: Interfacing biological machinery with electronics for biosensing and bioenergy devices

Living systems have very efficient mechanisms to carry out a number of useful tasks, such as energy generation, catalysis, logic functions, molecular recognition, motility, etc. These systems are not only efficient, they are also a good example of green and sustainable technology. It would be very useful if the molecular machinery that is responsible for these processes could be incorporated in man-made devices. However, biological molecules are fragile when taken out of their natural biological environment (the cell). We propose to develop gels, essentially water that is immobilised and structured by the incorporation of network of fibres with a precise molecular composition, that stabilise these biological molecules and allow them to be used in devices. The resulting technology will combine the advantages of biological systems (highly efficient and fully renewable) with those of synthetic materials (simple, low-cost and robust). Ultimately, we hope to use this technology to incorporate biology's energy supply mechanism, photosynthetic systems into gel particles.

Biomolecular machinery is capable of carrying out numerous useful tasks, including light harvesting and catalysis, with exquisite precision and efficiency. As a result, there is a significant current interest in incorporating these functional proteins into man-made devices, e.g. biosensors, lab-on-a-chip or green energy devices. However, functional proteins suffer from instability and reduced activity when removed from their natural environments, making their use in artificial devices challenging. Molecular hydrogels provide potentially ideal interfaces to integrate biomolecules into artificial devices. Beyond providing a hydrated immobilisation matrix, molecular hydrogels (contrary to their polymeric counterparts) are unique in providing a highly structured aqueous environment, which results in dramatic enhancement of hydrogen bond networks and ligand stabilisation, resulting in protein stabilisation. We will investigate whether the versatility of peptide chemistry will allow this gel environment to be matched, at the molecular level, with the specific surface properties of a protein of interest to enhance protein stability and activity. A second aspect that will be explored, is to explore charge transfer capabilities of designed gel phase materials, to provide an effective interface between biological components and electronics. To demonstrate proof of concept of this potential platform technology, we will test two proteins of relevance to future devices, that are both of interest for exploitation in devices but suffer severe limitations in stability: a light-harvesting complex and hydrogenase. The development of protein stabilising charge transfer gels represents an enabling technology that is expected to impact on a number of research areas were biological systems are to be interfaced with man-made structures.

The aim of this project is to tackle an adventurous scientific programme aimed at the development of a new class of functional soft matter which enables biological machinery to be effectively integrated into synthetic devices. The proposed functional materials, based on our pioneering hybrid synthetic/biomolecular aromatic peptide amphiphile technology, provide a highly flexible, size-matched, dynamic interface between biological systems and man-made materials. In the current proposal, we will focus on fundamental research. Towards the end of the grant we will investigate examples of relevance to green energy which will lead to eventual societal benefit.