Research Interests

Research group activity

Biospectroscopy and imaging

My research group’s aim is to bring frontier technologies in spectroscopy, imaging, photonics and microfluidics to bear on problems at the life-science interface.

A particular area of interest is the application of specialised techniques in fluorescence imaging to monitor the dynamics of single molecules. Differences in chemical reactivity might arise from small variations in the conformational structure of proteins and nucleic acids, however, the dynamics of individual molecules are not revealed in traditional experiments. Instead, the results reflect the ensemble average across the entire population of molecules. It is the objective of single-molecule research to reveal sub-population heterogeneity. With Professor Ian Eperon in Leicester, we are applying single molecule methods to address otherwise inaccessible problems in RNA splicing. These have included validation of the spice-site selection model and the pathways for the early stages of spliceosome assembly and 3′ splice-site selection. We have also invented a technique to encapsulate single biological molecules in aqueous microdroplets within a water-in-oil emulsion. The approach enables single molecule fluorescence measurements to be made on freely-diffusing molecules, and eliminates the normal requirement to tether molecules to a solid support (the technology has been patented by the University).

On a different theme within the research group, we apply a number of imaging modalities to quantifying the distribution of haem proteins in living cells, and how this distribution evolves in response to different stimulants. We are able to distinguish between the identity of the proteins, and the oxidation and coordination state of the metal. Using Raman imaging, we have been able to provide mechanistic evidence for how small molecules (NO, CO) might confer protection on cardiomyocytes (heart cells) via their interactions with haem proteins. We have also been looking at the regulatory role of haem in cells. We have designed a genetically-encoded sensors for measuring in vivo haem concentrations by fluorescence lifetime imaging and developed new fluorescence assays to probe the role of haem in the molecular mechanism of the transcription-translation feedback loops which are responsible for maintaining circadian rhythms.