Claire Vallance

Our group works in the general areas of chemical reaction dynamics and new spectroscopic methods and applications.  Our work ranges from fundamental studies of photon and electron-induced chemistry to the development of new types of chemical sensor and applications of spectroscopy in medicine.  Projects include:

1.    Photoinduced and electron-induced chemical reactions

We study photoinduced and electron-induced chemistry in the gas phase, using velocity-map imaging to record scattering distributions of reaction products and covariance-map imaging to investigate correlations between different products.  The measured scattering distributions provide a ‘fingerprint’ for the process under study, and can be analysed in order to unpick details of the reaction mechanism.  

2.     Ultrafast detectors for time-of-flight imaging

We are part of the PImMS (Pixel Imaging Mass Spectrometry) consortium, a group of researchers working to develop ultrafast imaging sensors suitable for applications in time-of-flight mass spectrometry.  The sensors allow velocity-map or spatial-map images to be acquired for each mass peak in a time-of-flight mass spectrum, opening up a range of new applications in mass spectrometry, state-of-the-art chemical dynamics studies, neutron detection, and other fields of science.  More information on the PImMS detectors is available here: pimms.chem.ox.ac.uk.

3.    Spectroscopic and mass spectrometric measurements in clinical medicine

We are working with clinicians and researchers in cardiology, vascular surgery, and neurosurgery at the John Radcliffe hospital to develop various types of spectroscopy for the analysis of clinical samples.  Projects include:  (i) evaluating whether reflectance spectra of coronary thrombus and/or mass spectra of coronary plasma can be used to classify heart attack patients into high and low risk groups, and therefore to guide clinical decisions during the acute treatment phase; (ii) investigating the use of Raman and fluorescence spectroscopy and mass spectrometry for the genetic characterisation of brain tumours and delineation of tumour borders; (iii) rapid mass spectrometric analysis of tissue from abdominal aortic aneurisms to identify clinically relevant biomarkers.

4.    Optical microcavities for chemical sensing

Over the past few years we have been working with Prof. Jason Smith's group in Oxford Materials to develop miniature optical cavities for applications in solution-phase chemical sensing and nanoparticle characterisation.