Dose-Dependent Vibrational Response of Short-Chain DNA to Gamma Irradiation Modulated by Magnesium Ions

Abstract Rapid and reliable detection of ionizing radiation exposure is an emerging area of research, as accurate assessment of radiation-induced biological damage is important for protecting both patients and healthcare workers. Here, we developed a controlled DNA-Mg²⁺ model coupled with Fourier transform infrared (FTIR) spectroscopy to detect radiation-induced molecular changes and to establish a foundation for spectroscopic absorbed-dose assessment. We investigated a controlled short-chain double-stranded DNA-Mg²⁺ model at three Mg/P ratios, irradiated with Co-60 γ rays over an absorbed-dose range of 0.3–100 Gy using a clinical Gamma Knife unit. Irradiation-induced changes were detected across nucleobase, sugar-phosphate and conformation-sensitive spectral regions. Importantly, we found that the multivariate spectral response retains information related to absorbed dose, and that this dose-associated response is strongly modulated by the Mg²⁺ environment. Our findings indicate that the identified dose-sensitive spectral regions, and their Mg²⁺-dependent modulation form a basis for spectroscopic absorbed-dose assessment. This provides a proof of concept for DNA-Mg²⁺-based FTIR molecular radiation sensing and supports the need for further development of this approach as a rapid and reliable method for assessing radiation exposure and estimating absorbed dose.