AVS 49th International Symposium
    Surface Science Wednesday Sessions
       Session SS-WeP

Paper SS-WeP7
S K-edge NEXAFS and S 1s XPS Studies of L-cysteine on Transition Metals

Wednesday, November 6, 2002, 11:00 am, Room Exhibit Hall B2

Session: Surface Science Poster Session
Presenter: Y. Matsumura, Nagoya University, Japan
Authors: Y. Matsumura, Nagoya University, Japan
S. Yagi, Nagoya University, Japan
Y. Nakano, Nagoya University, Japan
E. Ikenaga, Hiroshima University, Japan
S.A. Sardar, Hiroshima University, Japan
J.A. Syed, Hiroshima University, Japan
K. Soda, Nagoya University, Japan
E. Hashimoto, Hiroshima University, Japan
K. Tanaka, Hiroshima University, Japan
M. Taniguchi, Hiroshima University, Japan
Correspondent: Click to Email
We have paid attention to L-cysteine [HSCH@sub 2@CH(NH@sub 2@)COOH] and investigated the adsorption behavior on polycrystalline Cu, Mo and Ni substrates by S K-edge Near Edge X-ray Absorption Fine Structure (NEXAFS) and S 1s X-ray Photoelectron Spectroscopy (XPS) techniques. The sample was prepared by adsorbing L-cysteine molecules on clean metal surfaces in an aqueous solution at room temperature. Curve fitting of the S K-edge NEXAFS spectra reveals that there is a peak at around 2470eV. The NEXAFS spectra clarifies L-cysteine molecule dissociates for Ni. In the S 1s XPS spectra a sharp peak and a shoulder structure appear at around 2473eV and 2470eV, respectively. The peak deconvolution of the XPS spectra reveals the presence of three S chemical states, which are L-cysteine molecule, thiolate and atomic sulfur. The result of NEXAFS is consistent with that of XPS qualitatively. Keywords: NEXAFS, XPS, L-cysteine, adsorption behavior, Cu, Mo, Ni.