Projects
Projects: Projects for Investigator |
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| Reference Number | EP/J002577/1 | |
| Title | Electron attachment to biomolecular clusters: probing the role of multiple scattering in radio-sensitivity. | |
| Status | Completed | |
| Energy Categories | Nuclear Fission and Fusion(Nuclear Fission, Nuclear supporting technologies) 50%; Not Energy Related 50%; |
|
| Research Types | Basic and strategic applied research 100% | |
| Science and Technology Fields | BIOLOGICAL AND AGRICULTURAL SCIENCES (Biological Sciences) 25%; PHYSICAL SCIENCES AND MATHEMATICS (Chemistry) 50%; PHYSICAL SCIENCES AND MATHEMATICS (Physics) 25%; |
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| UKERC Cross Cutting Characterisation | Not Cross-cutting 100% | |
| Principal Investigator |
Dr SP Eden No email address given Physical Sciences Open University |
|
| Award Type | Standard | |
| Funding Source | EPSRC | |
| Start Date | 01 September 2011 | |
| End Date | 31 August 2016 | |
| Duration | 60 months | |
| Total Grant Value | £618,329 | |
| Industrial Sectors | No relevance to Underpinning Sectors | |
| Region | East of England | |
| Programme | NC : Physical Sciences | |
| Investigators | Principal Investigator | Dr SP Eden , Physical Sciences, Open University (100.000%) |
| Industrial Collaborator | Project Contact , Consejo Superior de Investigaciones Científicas (CSIC), Spain (0.000%) Project Contact , University of Nebraska-Lincoln, USA (0.000%) |
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| Web Site | ||
| Objectives | ||
| Abstract | The aim of this fellowship is to advance our understanding of how the chemical environment affects electron attachment to biomolecules. Electron attachment processes play an important role in radiation damage to biological material. In particular, electrons released by the ionization of local molecules (mainly water) can lose energy in a series of collisions before attaching to nucleobases in DNA. The resultant negative ions may be unstable and hence fragment yielding reactive species. A high density of such dissociation events in DNA constitutes a clustered lesion, recognised as a key precursor to mutations and cancers. Detailed knowledge of how electrons attach to biomolecules and the stabilities of the resultant anionic states is therefore essential to understand radiation damage on the molecular scale. Moreover characterising low-energy electron interactions with specific biomolecules can inform how manipulating their chemical environment with dopants can affect their radio-sensitivity with important applications in radiotherapy and radiation protection.The project will be centred on the development of an original experimental system to irradiate hydrogen-bonded biomolecular clusters with electrons at precisely defined energies (around 1meV to 15eV) and analyse the resultant anions by mass spectrometry. The key strength, novelty, and challenge will lie in applying the deflection of polar species in inhomogeneous electric fields (Stark deflection) to provide exceptional control over the target cluster configurations before the interactions with electrons. To date, direct comparisons with theory have been limited by the spread of neutral cluster sizes in experiments. The programme will be carried out in close collaboration with leading theoreticians (Gorfinkiel, OU, and Fabrikant, University of Nebraska) pioneering new methods to simulate electron scattering from / attachment to molecules within clusters. Electron interactions with specific neutral clusters will therefore be probed in equivalent experiments and calculations for the first time. The initial biomolecular targets will be complexes comprising water molecules, DNA bases, and a related azabenzene molecule, pyridine. Understanding the molecular-scale processes that initiate radiation damage in biological material has recently motivated extensive research into low-energy electron interactions with biomolecules. Experimental and theoretical studies of gas-phase biomolecules have revealed detailed information about the electron attachment sites and fragmentation patterns of specific anions. However hydrogen bonding can dramatically change the electron affinities of molecules as well as introducing new pathways for energy dissipation and electron loss from anionic states. The interpretation of experiments on biomolecular clusters without size selection and on condensed biomolecules is compromised by the lack of precise knowledge of the target and by dielectric surface charging, respectively. Size-selected neutral clusters provide a powerful test case to probe the effects of hydrogen bonding, notably by studying fragment anion production from a key biomolecule as a function of the precise number of associated water molecules. In summary, my objective is to develop a unique programme of experiments with strong theoretical support to advance our understanding of electron attachment processes in size-selected neutral clusters as model multi-molecular systems. This research will help to bridge the complexity gap between understanding radiation-induced processes in isolated molecules and in condensed material, with applications in modelling and potentially modifying biological damage processes on the nanoscale | |
| Publications | (none) |
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| Final Report | (none) |
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| Added to Database | 28/11/11 | |
