title: Electrochemical impedance spectroscopy and atomic force microscopic studies of electrical and mechanical properties of nano-black lipid membranes and size dependence.
abstract: 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.
authors.affiliation: 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.
authors.forename: Zai-Wen
authors.initials: ZW
authors.lastname: Zhu
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhang
authors.forename: Chun-Feng
authors.initials: CF
authors.lastname: Sun
authors.forename: Mian-Gang
authors.initials: MG
authors.lastname: Li
authors.forename: Jia-Wei
authors.initials: JW
authors.lastname: Yan
authors.forename: Bing-Wei
authors.initials: BW
authors.lastname: Mao
mesh_terms: D058266:Dielectric Spectroscopy; D004583:Electrons; D008051:Lipid Bilayers / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D017655:Silicon Compounds / Q000737:chemistry; D013499:Surface Properties
chemical_list: D008051:Lipid Bilayers; D017655:Silicon Compounds; C032734:silicon nitride