SKM 2023 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 11: Poster Session I
BP 11.8: Poster
Dienstag, 28. März 2023, 12:30–15:30, P1
The change of DNA radiation damage upon hydration: In-situ observations by near-ambient-pressure XPS — •Marc Benjamin Hahn1, Paul M. Dietrich2, and Jörg Radnik1 — 1undesanstalt für Materialforschung und -prüfung, Berlin, Germany. — 2SPECS Surface Nano Analysis GmbH, Berlin, Germany
X-ray photoelectron-spectroscopy (XPS) allows simultaneous irradiation and damage monitoring. Although water radiolysis is essential for radiation damage, all previous XPS studies were performed in vacuum. [1] Here we present near-ambient-pressure XPS experiments to directly measure DNA damage under water atmosphere. They permit in-situ monitoring of the effects of radicals on fully hydrated double-stranded DNA. Our results allow us to distinguish direct damage, by photons and secondary low-energy electrons (LEE), from damage by hydroxyl radicals or hydration induced modifications of damage pathways. The exposure of dry DNA to x-rays leads to strand-breaks at the sugar-phosphate backbone, while deoxyribose and nucleobases are less affected. In contrast, a strong increase of DNA damage is observed in water, where OH-radicals are produced. In consequence, base damage and base release become predominant, even though the number of strand-breaks increases further. [1] Hahn, M.B., Dietrich, P.M. & Radnik, J. In situ monitoring of the influence of water on DNA radiation damage by near-ambient pressure X-ray photoelectron spectroscopy. Commun Chem 4, 50 (2021).