Radiation-Induced Effect on Spin-Selective Electron Transfer through Self-Assembled Monolayers of ds-DNA

Abstract

Stability of the DNA molecule is essential for the proper functioning and sustainability of all living organisms. In this study, we investigate the effect of gamma radiation (γ-radiation) on spin-selective electron transfer through double strand (ds)DNA molecules. Self-assembled monolayers (SAMs) of 21-base long DNA are prepared on Au-coated Ni thin film. We measure the spin polarization (%) of the SAMs of ds-DNA using the spin-dependent electrochemical technique. We use a Cs-based γ-radiation source to expose the SAMs of ds-DNA immobilized on thin films for various time intervals ranging from 0–30 min. The susceptibility of DNA to γ-radiation is measured by spin-dependent electrochemistry. We observe that the efficiency of spin filtering by ds-DNA gradually decreases when exposure (to γ-radiation) time increases, and drops below 1% after 30 min of exposure. The change in spin polarization value is related either to the conformational perturbation in DNA or to structural damage in DNA molecules caused by ionizing radiation.