物理化学学报 >> 1998, Vol. 14 >> Issue (11): 968-974.doi: 10.3866/PKU.WHXB19981103

研究论文 上一篇    下一篇

金纳米粒子在氨基表面上的组装-pH值的影响

符小艺, 牟涛, 王健, 朱涛, 刘忠范   

  1. 北京大学化学与分子工程学院,智能材料研究中心,北京 100871
  • 收稿日期:1998-01-20 修回日期:1998-03-23 发布日期:1998-11-15
  • 通讯作者: 刘忠范

pH-Dependent Assembling of Gold Nanoparticles on p-Aminothiophenol Modified Gold Substrate

Fu Xiao-Yi, Mou Tao, Wang Jian, Zhu Tao, Liu Zhong-Fan   

  1. Center for Intelligent Materials Research(CIMR),College of Chemistry Molecular Engineering,Peking University,Beijing 100871
  • Received:1998-01-20 Revised:1998-03-23 Published:1998-11-15
  • Contact: Liu Zhong-Fan

摘要:

用原子力显微镜(AFM)和表面增强喇曼光谱(SERS)研究了pH值对金纳米粒子在Au/巯基苯胺自组装膜表面上组装效果的影响.AFM结果表明,金纳米粒子在表面上的覆盖度随pH值表现出规律性的变化,巯基苯胺自组装膜的SERS强度随pH值的变化也有类似的趋势.在磁性环境下,氨基未质子化,金粒子难以组装上,而在酸性条件下,氨基质子化带正电,金粒子与基底容易结合.我们认为金纳米粒子和氨基之间的作用属于静电力,pH值同时影响膜表面氨基的质子化程度和金纳米粒子表面的带电量.

关键词: 金纳米粒子, 自组装膜, AFM, SERS

Abstract:

Au nanoparticles are assembled on gold substrate modified with p-aminothiophenol. AFM measurements show that the coverage of Au nanoparticles is closely related to the pH value of colloids. The SERS intensity also changes with the pH value, which is well consistent with the pH-dependent change of the coverage. In alkaline solution, the amino group is not protonated, and Au particles can not be adsorbed on the substrate: while under acidic environment, protonation makes the amino group positively charged and the adsorption gets easier. The interaction between the particles and the substrate is considered to be electrostatic. The PH value, which controls the coverage of Au nanoparticles, affects both the protonation of the amino group and the quantity of the negative charge of Au particles.

Key words: Au nanoparticles, Self-assembly, AFM, SERS