TY - JOUR A1 - Rackwitz, J. A1 - Rankovic, M. A1 - Milosavljevic, A. A1 - Bald, Ilko T1 - A novel setup for the determination of absolute cross sections for low-energy electron induced strand breaks in oligonucleotides – The effect of the radiosensitizer 5-fluorouracil JF - European Physical Journal D N2 - Low-energy electrons (LEEs) play an important role in DNA radiation damage. Here we present a method to quantify LEE induced strand breakage in well-defined oligonucleotide single strands in terms of absolute cross sections. An LEE irradiation setup covering electron energies <500 eV is constructed and optimized to irradiate DNA origami triangles carrying well-defined oligonucleotide target strands. Measurements are presented for 10.0 and 5.5 eV for different oligonucleotide targets. The determination of absolute strand break cross sections is performed by atomic force microscopy analysis. An accurate fluence determination ensures small margins of error of the determined absolute single strand break cross sections σSSB. In this way, the influence of sequence modification with the radiosensitive 5-Fluorouracil (5FU) is studied using an absolute and relative data analysis. We demonstrate an increase in the strand break yields of 5FU containing oligonucleotides by a factor of 1.5 to 1.6 compared with non-modified oligonucleotide sequences when irradiated with 10 eV electrons. KW - DNA origami KW - DNA radiation damage KW - Radiosensitizer KW - AFM KW - Fluorouracil PY - 2017 UR - http://epjd.epj.org/articles/epjd/abs/2017/02/d160608/d160608.html DO - https://doi.org/10.1140/epjd/e2016-70608-4 VL - 71 SP - 32 PB - Springer CY - New York, NY, USA AN - OPUS4-39643 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -