Dissociative electron attachment to DNA-diamine thin films: Impact of the DNA close environment on the OH(-) and O(-) decay channels.

Omar Boulanouar (1) , Michel Fromm (1) , Christophe Mavon (1) , Pierre Cloutier (2) , Léon Sanche (2)

1 LCE - Laboratoire Chrono-environnement (UMR 6249)
2 Centre for Research in Radiooncology

: We measure the desorption of anions stimulated by the impact of 0-20 eV electrons on highly uniform thin films of plasmid DNA-diaminopropane. The results are accurately correlated with film thickness and composition by AFM and XPS measurements, respectively. Resonant structures in the H(-), O(-), and OH(-) yield functions are attributed to the decay of transient anions into the dissociative electron attachment (DEA) channel. The diamine induces ammonium-phosphate bridges along the DNA backbone, which suppresses the DEA O(-) channel and in counter-part increases considerably the desorption of OH(-). The close environment of the phosphate groups may therefore play an important role in modulating the rate and type of DNA damages induced by low energy electrons.

Domaines: Chimie théorique et/ou physique

Omar Boulanouar, Michel Fromm, Christophe Mavon, Pierre Cloutier, Léon Sanche. Dissociative electron attachment to DNA-diamine thin films: Impact of the DNA close environment on the OH(-) and O(-) decay channels.. Journal of Chemical Physics, 2013, 139 (5), pp.055101. ⟨10.1063/1.4815967⟩. ⟨hal-00858438⟩