Tailoring the electrode-enzyme interface for efficient bioelectrochemical CO2 reduction by formate dehydrogenase

The main objective of this proposal is to optimize the enzyme-electrode interface to achieve efficient bioelectrochemical carbon dioxide (CO2) reduction by formate dehydrogenase (FDH).

To achieve the overall goal of the proposed project, the specific objectives are: 1) Incorporation of an unnatural amino acid (UAA) to Molybdenum-containing FDH (Mo-FDH) such that the enzyme can be specifically and covalently attached to electrode surfaces with controlled orientation for improved electron transfer (ET) 2) Tailoring the bio-interface between electrodes and FDH H for facile electrocatalysis by direct ET (DET) or mediated ET (MET).

This includes the design electrode surface with pyrene moieties/mediator for directing orientation of biocatalysts on electrode surfaces. 3) Bioelectrosynthetic CO2 capture with electrochemical systems exploiting UAA-FDH H.

For this, the prepared UAA containing Mo-FDH based biocathodes will be coupled with a hydrogenase bioanode to provide a complete enzymatic biofuel cell (EBFC) producing formate (HCOO− )and simultaneously producing electrical energy from molecular hydrogen (H2) and CO2. The project will be conducted in 3 work packages associated with research objectives.

An UAA will be introduced to FDH H for the first time, yielding an approach for site-specific functionalization of complex metalloenzymes with this project.

The proposed technology is highly attractive because it presents a promising solution to tackle global climate issues and energy concerns by providing improved green conversion of CO2 to chemical fuels.

This project will be undertaken within the group of Professor Ross Milton (University of Geneva, Switzerland) and a secondment of two months is planned with Prof. Jason Chin (MRC Laboratory of Molecular Biology, Cambridge, UK) in order to develop skills in UAA incorporation.