Surface-conditioning effect of gold substrates on octadecanethiol self-assembled monolayer growth
Surface-conditioning effect of gold substrates on octadecanethiol self-assembled monolayer growth
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DOI：
10.1021/la970241t
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发表时间：
1997-08-20
期刊：
影响因子：
3.9
通讯作者：
Knoll, W
中科院分区：
文献类型：
--
作者：
Ishida, T;Tsuneda, S;Knoll, W
用X射线光电子能谱(XPS)研究了金衬底对正十八烷硫醇(ODT)自组装单分子膜(SAM)生长的表面修饰作用。将金衬底在含1 mM ODT的乙醇溶液中浸泡1h，用XPS测定在金衬底上形成的ODT自组装膜的C/Au比取决于金表面的污染量。紫外光(UV)/臭氧处理1h，无水乙醇漂洗1h后，在金表面成功地得到了完全覆盖的ODT SAM，XPS测试表明，采用这种前处理方法得到的金表面污染小，表面无硫，有效地实现了ODT分子在金表面的吸附.另一方面，由于表面污染可能会降低ODT分子在金表面的吸附速率，因此在受污染的金衬底上，ODT SAM在ODT溶液中浸泡1h后，其C/Au比较小。当金衬底在形成SAM之前用氯仿溶液清洗1h时，获得了最低的C/Au比。XPS结果表明，氯仿洗涤后，硫原子迅速吸附到金表面，阻碍了ODT分子在金表面的吸附。
The surface-conditioning effect of gold substrates on n-octadecanethiol (ODT) self-assembled monolayer (SAM) growth was studied by X-ray photoelectron spectroscopy (XPS). The gold substrates were immersed in an ethanol solution containing 1 mM ODT for 1 h. The C/Au ratios of the ODT SAMs estimated by XPS formed on gold substrates depended on the amount of contamination on the gold surface. A full-coverage ODT SAM was successfully obtained on the gold substrate after ultraviolet light (UV)/ozone treatment for 1 h and rinsing with pure ethanol for 1 h. XPS measurements indicated that low contamination levels and a sulfur-free gold surface were obtained using this pretreatment and, hence, the adsorption of ODT molecules on gold proceeded efficiently. On the other hand, the C/Au ratio of an ODT SAM on a contaminated gold substrate was less following immersion in an ODT solution for 1 h, because surface contamination may reduce the adsorption rate of ODT molecules on the gold surface. When the gold substrate was rinsed with a chloroform solution for 1 h before SAM formation, the lowest C/Au ratio was obtained. XPS results showed that sulfur atoms quickly adsorbed onto the gold surface after chloroform rinsing and prevented the adsorption of ODT molecules onto the gold surface.