Dissociative electron attachment to DNA-diamine thin films: impact of the DNA close environment on the OH- and O- decay channels.
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.
UMR CNRS 6249 Chrono-Environnement, Laboratoire de Chimie Physique et Rayonnements - Alain Chambaudet, LRC CEA, Université de Franche-Comté, 16 route de Gray, F-25030 Besançon cedex, France.
Omar
O
Boulanouar
Michel
M
Fromm
Christophe
C
Mavon
Pierre
P
Cloutier
Léon
L
Sanche
D004247:DNA / Q000737:chemistry*; D003959:Diamines / Q000737:chemistry*; D004583:Electrons; D006878:Hydroxides / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D010957:Plasmids
D003959:Diamines; D006878:Hydroxides; D004247:DNA; C031356:hydroxide ion; D010100:Oxygen