Journal article
Novel analytical study for reaction intermediates in the primary radiation interaction of dna using a synchrotron radiation-induced luminescence spectroscopy



Publication Details
Authors:
Kojima, T.; Aihara, H.; Kodashima, Y.; Makishima, H.; Nakiri, S.; Takada, S.; Shimada, H.; Ukai, M.; Ozga, C.; Holzapfel, X.; Schmidt, P.; Küstner-Wetekam, C.; Otto, H.; Bloß, D.; Knie, A.; Ehresmann, A.; Yokoya, A.; Fujii, K.; Fukuda, Y.; Saitoh, Y.
Publication year:
2019
Journal:
Radiation Protection Dosimetry
Pages range:
ncy239
Volume number:
2019
ISSN:
0144-8420
Languages:
English

Abstract
To identify the precise molecular processes to induce DNA lesions, we attempt a novel spectroscopy of X-ray induced luminescence (XIL) using soft X-ray synchrotron radiation, which is a non-destructive analysis of the reaction intermediates in the elementary reaction pathway of damage induction and self-organized restoration. Using a liquid micro-jet technique to introduce aqueous samples in a vacuum chamber, we measure UV-visible luminescence from nucleotide solution as a function of the soft X-ray energy from the nitrogen to oxygen K-edge region. The LEX intensities for the nucleotide solutions are significantly enhanced in the soft X-ray region (410-530 eV) which is ascribed to the K-shell excitation/ionization of nitrogen atoms in the nucleobases. Furthermore, the LEX spectra do not show any signature of X-ray absorption near-edge structure (XANES) of the nucleobases. This is because the luminescence intensities collected from the integral area of the micro-jet only reflect the quantum yield of luminescence of the absorbed X-ray into UV-visible light irrespective of the absorption cross sections, i.e. of XANES. Thus the present result is the first evidence of luminescence as a result of X-ray absorption of aqueous nucleotides.

Last updated on 2019-11-03 at 09:04