Korea Research Institute of Standards and Science, Daejeon 305-340, Korea.
Langmuir. 2010 Apr 20;26(8):5632-6. doi: 10.1021/la904496j.
Adsorption behaviors of sulfur-containing amino acids, cysteine, methionine, and cystine molecules on Cu(110) surface were studied by core level photoelectron spectroscopy using synchrotron radiation. We found the following through the systematic comparisons of core level peaks such as S 2p, N 1s, and O 1s from different amino acids. At low coverage regimes, all the molecules form two distinct thiolate species, and their S 2p binding energy difference was about 0.9 eV. The relative populations of the two thiolates were different for different molecules and their coverage, which is due to the different bond strength of the sulfur-containing functional groups. At high coverage regimes, only cysteine molecules form zwitterionic state, which is related to the molecular ordering on Cu(110) surface.
利用同步辐射的芯层光电子能谱研究了含硫氨基酸半胱氨酸、蛋氨酸和胱氨酸分子在 Cu(110)表面的吸附行为。通过对不同氨基酸的 S 2p、N 1s 和 O 1s 等芯层峰的系统比较，我们发现：在低覆盖度时，所有分子都形成两种不同的硫醇盐物种，它们的 S 2p 结合能差约为 0.9 eV。对于不同的分子和覆盖度，两种硫醇盐的相对比例不同，这是由于含硫官能团的键强度不同。在高覆盖度时，只有半胱氨酸分子形成两性离子态，这与 Cu(110)表面上的分子有序性有关。
