Advanced transmission electron microscopy imaging and spectroscopy of graphene based materials for biomedical applications

The development of nanomaterials for biomedical and pharmaceutical applications has the potential to provide breakthrough to medical technologies such as improved drug delivery and theranostic devices. Among graphene based materials, graphene oxide (GO) is a particularly interesting 2D material for biomedicine because of its dispersibility in aqueous environments and its ability to be controllably functionalised to create GO based materials (GOBMs) with chemically distinct markers.

Before considering the translation of GOBMs as drug-delivery vectors to the pharmaceutical industry, it is of critical importance to understand the toxicological limitations and in vivo biodegradability of GOBMs in living system. This requires visualising and locating GOBMs at the ultrastructural level (within the cell), which is very challenging using current characterisation techniques such as conventional TEM or optical microscopies without attaching an imaging tag to GOBM basal plan. The first goal of this project will be to develop a methodology allowing reliable and robust characterisation of GOBMs at the ultrastructural level of different animal cells and tissues, starting with our promising early results. Then, this novel methodology will be used to investigate the interaction of GOBMs with the cellular milieu to get insight into biological mechanism occurring at the nanometer scale. This project will mainly employ (scanning) transmission electron microscopy ((S)TEM) imaging and spectroscopy techniques, such as X-ray energy dispersive spectroscopy (EDS) and electron energy loss spectroscopy (EELS), in combination with confocal Raman spectroscopy imaging and Confocal Laser Scanning Microscopy for correlative purpose.

You will have access to the STEM-EDS and the electron tomography instrumentation available in the School of Materials (FEI Talos ChemiSTEM) and the STEM-EELS at the SuperSTEM laboratory (Nion UltraSTEM). One of the strengths of this project is to use advanced TEM imaging and spectroscopic techniques, unique in Europe, on interesting biological samples generated at the co-supervisors’ labs. In particular, the recent development of the monochromator in the STEM available at the SuperSTEM (ERPSC national facility in Daresbury) provides a ~50× improvement in energy resolution, which will facilitate perform cutting-edge experiments, such as measuring the biodegradability of GOBMs in vivo using high-resolution EELS. Combining these novel experiments with sophisticated data analysis will lead to a clearer understanding of the interactions of GOBMs with the cellular milieu, which have been up to now very challenging to investigate.

During this PhD, the candidate will have the opportunity to develop experimental skills and knowledge on graphene-based materials and on a range of characterisation techniques (electron microscopies, Raman spectroscopy, correlative techniques, etc.). This project will require advanced data analysis and modelling of TEM imaging and spectroscopy, done independently or in collaboration with experts. There is also the opportunity to develop computer programming skills.

Applicants should have or expect to achieve at least a 2.1 honours degree in Materials Science, Physics, Chemistry or a related subject.