Romain Castra : Gold nanoparticle electron and photon emissions after X-ray absorption
|When:||Th 19-03-2015 11:00 - 12:00|
Gold nanoparticle have been increasingly used as radiosensitizer for cancer therapy in the last years and a lot of experimental work has been devoted to explaining why they effectively enhance the effect of radiotherapy treatments but the answer to this question remains elusive. Nevertheless, it seems that nanoparticle electron and photon emissions play a major role in the radiosensitization process: the absorption by the nanoparticles of the radiotherapy photon energy and its re-emission in the form of electrons and/or photons of lower energies causing damages to the cancerous cells is one the most admitted theories.
One of the key features to understand this radiosensitizing effect is the energy spectra of the electrons and photons from the gold nanoparticles. We present both experimental and theoretical studies evaluating these spectra : from the experimental point of view, we performed X-ray spectroscopy experiments on a commercial XPS apparatus and with our home-made XPS, allowing to reach the 1-10eV energy range. We also present a model we developed to evaluate nanoparticle photon and electron emission from Auger transition rates, stopping power and photoionisation subshell cross-sections.