Our aim is to develop novel electrode materials, including nanoparticles, that interact directly with redox enzymes, cell membranes or whole bacteria. This technology either serves as a platform for the development of diagnostics/biosensors and fuel cells or to study the catalytic mechanism of redox-active membrane proteins. The electrode materials, which include ”membrane-modified electrodes”, are characterised with a broad spectrum of biophysical tools. Using electrochemical tools, the electron transport activity of redox enzymes in the membranes is directly converted into a measurable current enabling the detailed study of the enzymes. By combining our electrochemical methods with fluorescent techniques, we aim to obtain information about processes normally not detected by electrochemistry, such as proton pumping or the redox state of single redox site in a multisite enzyme.
We have modified electrodes with lipid membranes in which the membranes either adopt a planar geometry (see Figures below) or liposomes are immobilised intact on the surface. This allows us to study redox-active membrane proteins in their native environment. We have four projects in this area.
In this theme we aim to control interactions between nanoparticles and cell membranes for biotechnology, including solar fuel production. In these hybrid systems, nanoparticles can act as photosensitisers that harvest the light and enzymes as the biocatalysts to convert light energy into high-value products. Alternatively, soft matter can be incorporates to create hybrid polymer/lipid vesicles for the stabilisation of membrane enzymes.
Many biosensors rely on the concept that biomarkers (analytes) bind with high specificity to antibodies or antibody mimetics such as Affimers. This binding is a passive event and in itself does not lead to an easily detectable signal. In this theme we aim to expand biosensor concepts by innovative ways by creating active binding proteins, which activate upon binding to a specific biomarker, automatically resulting in a detectable signal, detected colorimetrically, by fluorescence or electrochemically.