https://doi.org/10.1140/epjd/s10053-025-01068-w
Regular Article - Atoms, Molecules, Ions, and Clusters
Interaction of 25 eV electrons with DNA constituents: XPS analysis of calf thymus DNA, nucleosides, and nucleobases
1
CEFITEC, Departamento de Física, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516, Caparica, Portugal
2
Radiation Laboratory, University of Notre Dame, 46556, Notre Dame, IN, USA
3
Department of Chemistry and Biochemistry, University of Notre Dame, 46556, Notre Dame, IN, USA
4
Department of Physics and Astronomy, University of Notre Dame, 46556, Notre Dame, IN, USA
a
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Received:
25
June
2025
Accepted:
15
September
2025
Published online:
6
October
2025
Abstract
Understanding the interactions of secondary electrons generated by ionizing radiation provides a fundamental basis for developing strategies in cancer therapy. In this study, we investigated the interactions of 25 eV low-energy electrons (LEEs) with calf thymus DNA and its constituents, four types of nucleosides and nucleobases, using X-ray photoelectron spectroscopy (XPS). Based on the acquisition and analysis of core-level spectra (O 1s, C 1s, N 1s, and P 2p) in DNA, structural changes induced by 25 eV electrons suggest potential site- and base-specific selectivity. These changes may involve hydroxyl (C–OH) group release from the sugar moiety, cleavage of C–N bonds (likely corresponding to N-glycosidic linkages), and phosphate backbone damage in calf thymus DNA. Among the four nucleosides, thymidine and guanosine showed more evident structural modifications, while cytidine and adenosine were relatively stable. In addition, nucleosides displayed greater susceptibility to LEE-induced structural changes than their corresponding nucleobases. This study reveals the selective damage mechanisms of LEEs on various DNA constituents, which may provide mechanistic insights for future developments in precision cancer therapy based on molecular-level damage.
Supplementary Information The online version contains supplementary material available at https://doi.org/10.1140/epjd/s10053-025-01068-w.
© The Author(s) 2025
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