Low-energy electron damage of DPPC molecules- a NEXAFS study

In cancer research the radiation dose delivered to different organs presents a critical parameter for destroying the cancer cells' DNA, but the biochemical pathways that bring cells to death in many cases start at the cell membrane whose major part consists of lipid molecules.In our XPS and NEXAFS experiment, we exposed a monolayer lipid film supported on gold to a spatially and energetically well defined electron beam (20 eV), simulating the charged particle avalanche produced in the exposure of the biological tissue to a high-energy ionizing radiation (X-and  -rays, ions, etc).Oxygen and nitrogen 1s edge scans show a clear chemical degradation of the DPPC monolayer.The major damage has been inflicted to the polar head of the molecule and its links with the molecules' alkane chains.