高等学校化学学报 ›› 2025, Vol. 46 ›› Issue (2): 20240402.doi: 10.7503/cjcu20240402

• 分析化学 • 上一篇    下一篇

基于单颗粒碰撞电化学的烷硫醇在纳米金表面的自组装行为

白乙艳(), 王晨阳, 高阳, 李佳敏, 杨海英()   

  1. 运城学院应用化学系,运城 044300
  • 收稿日期:2024-08-26 出版日期:2025-02-10 发布日期:2024-10-25
  • 通讯作者: 白乙艳 E-mail:byy@ycu.edu.cn;hyyang@ycu.edu.cn
  • 作者简介:杨海英, 女, 博士, 教授, 主要从事电分析检测方面的研究. E-mail: hyyang@ycu.edu.cn
  • 基金资助:
    山西省应用基础研究项目(202203021212173);来晋奖励项目(QZX-2022001);山西省高等学校科技创新项目(2022L471);运城学院博士科研启动项目(YQ-2021032);运城学院化学学科资助

Alkanethiol Self-assembly Behavior on Gold Nanoparticles Based on Single-nanoparticle Collision Electrochemistry

BAI Yiyan(), WANG Chenyang, GAO Yang, LI Jiamin, YANG Haiying()   

  1. Department of Applied Chemistry,Yuncheng University,Yuncheng 044300,China
  • Received:2024-08-26 Online:2025-02-10 Published:2024-10-25
  • Contact: BAI Yiyan E-mail:byy@ycu.edu.cn;hyyang@ycu.edu.cn
  • Supported by:
    the Applied Basic Research Program of Shanxi Province, China(202203021212173);the Reward Program for Coming to Shanxi, China(QZX-2022001);the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi, China(2022L471);the Yuncheng University Doctoral Research Launch Project, China(YQ-2021032);the Chemistry Department of Yuncheng University, China

摘要:

采用单颗粒碰撞电化学分析法, 通过检测溶液中分散的单个颗粒, 探究了烷硫醇在纳米金(Au NPs)表面的自组装动力学过程, 以及组装过程中反应温度、 烷硫醇浓度和分子结构对其组装行为的影响. 结果表明, 烷硫醇自组装单分子层的形成使得Au NPs的活性面积减小, 从而导致其催化析氢电流下降. 基于此, 对比不同自组装条件下测得的碰撞信号, 发现吸附量在一定范围内随烷硫醇浓度及反应温度的升高而增大. 控制反应时间为10 min, 当6-巯基-1-己醇(6-MCH)的浓度为73 mmol/L, 反应温度为45 ℃时, 6-MCH在Au NPs表面吸附最多. 此外, 通过对比6-MCH、 3-巯基-1-丙醇(3-MCP)及3-巯基丙酸(3-MPA)的自组装动力学曲线, 发现自组装过程均由快速吸附及缓慢重组组成. 由于3-MPA的功能头基(羧酸根)与Au NPs的柠檬酸配体之间存在较强的静电排斥作用, 使得3-MPA的吸附量明显低于其它两种分子. 3-MCP与6-MCH的最大吸附量基本相同, 但由于6-MCH的烷基链更长、 疏水性更强及运动更慢, 导致其与Au NPs亲水性柠檬酸配体之间的作用更弱(6-MCH的吸附自由能变比3-MCP高约4.0 kJ/mol), 所以较晚达到吸附最大值.

关键词: 自组装, 单颗粒检测, 烷硫醇, 纳米金

Abstract:

The self-assembly kinetics of alkanethiol on the surface of gold nanoparticles(Au NPs) was investigated by detecting dispersed individual particles in the solution based on single-nanoparticle collision electrochemistry, as well as the effects of reaction temperature, alkanethiol concentration, and molecular structure on their assembly behavior during the assembly process. The results showed that the formation of self-assembled monolayers of alkanethiol reduced the active area of Au NPs, leading to a decreased current intensity for catalyzing hydrogen evolution. Based on this, comparing the current transients of different self-assembly conditions, it was found that the increase of adsorption amount was correlated positively with the concentration of alkanethiol and the reaction temperature within limits. Controlling the reaction time to 10 min, when the concentration of 6-mercapto-1-hexanol (6-MCH) was 73 mmol/L and the reaction temperature is 45 ℃, 6-MCH adsorbed the most amount on Au NPs. Furthermore, by comparing the self-assembly kinetics curves of 6-MCH, 3-mercapto-1-propanol(3-MCP), and 3-mercaptopropionic acid(3-MPA), it was found that the self-assembly process consisted of diffusion controlled rapid adsorption and slow recombination. Due to the strong electrostatic repulsion between the functional head group (carboxylate) of 3-MPA and the citric acid ligand of Au NPs, the adsorption capacity of 3-MPA was significantly lower than that of the other two molecules. The maximum adsorption capacity of 3-MCP and 6-MCH was basically the same, but due to the longer alkyl chain of 6-MCH, its adsorption free energy change was about 4.0 kJ/mol higher than that of 3-MCP, and it eventually reached the maximum adsorption value later.

Key words: Self-assembly, Single-particle detection, Alkanethiol, Au NPs

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