ABSTRACT
This chapter shows how secondary electrons can damage DNA and its constituents. DNA is composed of the four nucleobases guanine (G), adenine (A), cytosine (C), and thymine (T) and a backbone of alternating phosphate and 2'-deoxyribose units. Two DNA strands are coupled by hydrogen bonds between the complementary nucleobases G-C and A-T to form the well-known DNA double helix. More important than the damage caused by direct excitation of DNA nucleobases is the damage due to secondary reactive species that are formed by ionization of molecules in the vicinity of DNA. One experimental technique to form more complex targets than small building blocks for low-energy electron interaction are cluster expansions. A central challenge in the investigation of irradiated oligonucleotides is the small penetration depth of low-energy electrons and the resulting small amount of damaged material. The detection scheme for low-energy-electron-induced strand breaks is schematically.
