X-ray radiation of poly-L-arginine hydrochloride and multilayered DNA-coatings

The aim of this work was to determine the chemical changes induced in thin films of the dry polypeptide poly-L-arginine hydrochloride and its mixture with calf thymus deoxyribonucleic acid (DNA) during 5 h of soft X-ray exposure. The physical and chemical effects of the soft X-ray irradiation were studied using X-ray Photoelectron Spectroscopy (XPS). Analysis of O1s, N1s and C1s features in XPS spectra reveals the existence of several routes of radiation-induced decomposition and shows quantitative and qualitative changes.