State Key Laboratory of Physical Chemistry of the Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, PR China.
Langmuir. 2012 Oct 16;28(41):14739-46. doi: 10.1021/la303047v. Epub 2012 Oct 1.
We present electrochemical impedance spectroscopic (EIS) and two-chamber AFM investigations of the electrical and mechanical properties of solvent-containing nano-BLMs suspended on chip-based nanopores of diameter of 200, 400, and 700 nm. The chips containing nanoporous silicon nitride membranes are fabricated based on low-cost colloidal lithography with low aspect ratio of the nanopores. BLMs of DPhPC lipid molecules are constructed across the nanopores by the painting method. Two equivalent circuits are compared in view of their adequacy in description of the EIS performances of the nano-BLMs and more importantly the structures associated with the nano-BLMs systems. The BLM resistance and capacitance as well as their size and time dependence are studied by EIS. The breakthrough forces, elasticity in terms of apparent spring constant, and lateral tension of the solvent-containing nano-BLMs are investigated by AFM force measurements. The exact relationship of the breakthrough force of the nano-BLM as a function of pore size is revealed. Both EIS and AFM studies show increasing lifetime and mechanical stability of the nano-BLMs with decreasing pore size. Finally, the robust 200 nm diameter nanopores are used to accommodate functional BLMs containing DPhPC lipid molecules and gramicidins by using a painting method with drop of mixture solutions of DPhPC and gramicidins. EIS investigation of the functional nano-BLMs is also performed.
我们展示了电化学阻抗谱（EIS）和双室原子力显微镜（AFM）对溶剂纳米 BLM 悬浮在直径为 200、400 和 700nm 的基于芯片纳米孔上的电学和力学性能的研究。基于低纵横比的胶体光刻技术制造了含有氮化硅纳米多孔膜的芯片。通过涂覆法在纳米孔上构建 DPhPC 脂质分子的 BLM。比较了两个等效电路，以评估它们在描述纳米 BLM 的 EIS 性能方面的适当性，更重要的是，评估它们与纳米 BLM 系统相关的结构的适当性。通过 EIS 研究了 BLM 电阻和电容，以及它们的尺寸和时间依赖性。通过 AFM 力测量研究了含溶剂的纳米 BLM 的击穿力、表观弹性常数（即弹性）和横向张力。揭示了纳米 BLM 的击穿力与孔径的精确关系。EIS 和 AFM 研究均表明，随着孔径的减小，纳米 BLM 的寿命和力学稳定性增加。最后，使用 DPhPC 和 gramicidins 的混合物溶液滴涂法，在稳健的 200nm 直径纳米孔中容纳了含有 DPhPC 脂质分子的功能性 BLM。还对功能性纳米 BLM 进行了 EIS 研究。
