Photoelectron spectroscopic study on the electronic structures of the dental gold alloys and their interaction with L-cysteine

Abstract

The valence electronic structures of the dental gold alloys, type 1, type 3, and K14, and their interaction with L-cysteine have been studied by ultraviolet photoelectron spectroscopy with synchrotron radiation. It was found that the electronic structures of the type-1 and type-3 dental alloys are similar to that of polycrystalline Au, while that of the K14 dental alloy is much affected by Cu. The peak shift and the change in shape due to alloying are observed in all the dental alloys. It is suggested that the new peak observed around 2 eV for the L-cysteine thin films on all the dental alloys may be due to the bonding of S 3sp orbitals with the dental alloy surfaces, and the Cu–S bond, as well as the Au–S and Au–O bonds, may cause the change in the electronic structure of the L-cysteine on the alloys.

Interface Electronic Structures of the L-Cysteine on Noble Metal Surfaces Studied by Ultraviolet Photoelectron Spectroscopy

“…However, this interface state is difficult to be distinguished in their results; they consider the conclusion to be an assumption limited by weak emission under the experimental conditions. Further, Ogawa, et al [33,34] has performed UPS to study the electronic structures of dental alloys and their interaction with Lcysteine. In the study, they have performed UPS of vacuum evaporated thin films of nominal thickness 3Å and thick films of nominal thickness 60Å on polycrystalline Au, Ag, Pd, Cu in order to analyze L-cysteine interaction with dental alloys.…”

“…Therefore, an understanding of the interaction of L-cysteine with metal surfaces is necessary. There have been experimental and theoretical research studies that examined the behavior of L-cysteine adsorbed on different faces of gold [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19], silver [20][21][22][23], and copper [24][25][26] metallic single crystals as model systems for understanding the interaction of L-cysteine with metal surfaces and also L-cysteine adsorbed on some other surfaces considering technological interests [27][28][29][30][31][32][33][34][35]. In the experimental studies, the L-cysteine sample for investigation was formed using either the self-assembly or evaporation method.…”

Occupied and unoccupied electronic structures of an L-cysteine film studied by core-absorption and resonant photoelectron spectroscopies

“…7 taken from Ref. 12, the lowest unoccupied molecular orbital (LUMO) state of a cysteine molecule in our calculation has a large charge distribution on oxygen atoms and also small distributions on sulfur, carbon, and nitrogen atoms. The LUMO state shown in Fig.…”

“…11,12 The change in valence structures is interpreted in terms of the partial density of states (DOS) in the valence states. The enhancement of the peak b ′ is in good agreement with the calculated large distribution of oxygen 2sp orbitals around the peak b and the small contribution to the peak a.…”

“…11 Moreover, the chemical reactions between a thin L-cysteine film on the surface of dental alloys have been measured by UPS, showing the interesting interaction of L-cysteine with dental alloys. 12,13 Especially L-cysteine on silver metal indicates photo-induced transition depending on the sample temperature and excitation photon energy.…”