Photoemission Study of Thymidine Adsorbed on Au(111) and Cu(110)

摘要

The adsorption geometry of the DNA nucleoside thymidine on Au(111) and Cu(110) surfaces has been determined from experimental results of soft X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The XPS of C, N, and O 1s as well as the absorption spectra at the N and O K-edges were measured for monolayer thymidine films, and the nature of the bonding with the two metal surfaces has been determined. The NEXAFS data at the N and O K-edge show a strong angular dependence of the π~*/σ~* intensity ratios. We conclude that the thymine moiety is lying nearly parallel to the Au(111) surface, while on the Cu(110) surface, it adsorbs at a steep angle.