Characterization of Robust and Free-Standing 2D-Nanomembranes of UV-Polymerized Diacetylene Lipids.
Characterization of Robust and Free-Standing 2D-Nanomembranes of UV-Polymerized Diacetylene Lipids.
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紫外聚合二乙炔脂质的坚固且独立的二维纳米膜的表征
DOI：
10.1021/acs.langmuir.7b03403
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
D. Anselmetti
中科院分区：
文献类型：
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作者：
R. Hillmann;M. Viefhues;L. Goett-Zink;D. Gilzer;Th. Hellweg;A. Gölzhäuser;T. Kottke;D. Anselmetti
自支撑类脂膜作为人工功能膜系统在分离、过滤、纳米孔传感等方面具有广阔的应用前景。为了改善脂膜的机械性能，人们引入了紫外光聚合脂类。我们研究了1-palmitoyl-2-(10，12-tricosadiynoyl)-sn-glycero-3-phosphoethanolamine(PTPE)和1，2-bis(10，12-tricosadiynoyl)-sn-glycero-3-phosphocholine(DiynePC)的自立单分子膜和底物支撑单分子膜，并对它们的结构、形态和稳定性进行了表征。使用氦离子显微镜(HIM)，我们能够在高真空条件下观察跨越微米大小的空隙的脂类2D纳米膜的完整性。原子力显微镜在环境条件下的研究表明，形成了完整的、坚固的跨孔2D纳米膜，尺寸高达8×2μm2。衰减全反射傅里叶变换红外光谱(ATR-FTIR)分析表明，紫外光聚合后，2D纳米膜中二乙炔基团在2143 cm-1处的信号明显减弱。进一步的高分辨率AFM研究表明，当沉积在高度定向的热解石墨(HOPG)上时，未聚合的脂单分子膜具有良好的二维网络。这些结构在聚合层中被抑制。提出并讨论了分子排布的结构模型。
Free-standing lipid membranes are promising as artificial functional membrane systems for application in separation, filtration, and nanopore sensing. To improve the mechanical properties of lipid membranes, UV-polymerized lipids have been introduced. We investigated free-standing as well as substrate-supported monolayers of 1-palmitoyl-2-(10,12-tricosadiynoyl)-sn-glycero-3-phosphoethanolamine (PTPE) and 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine (DiynePC) and characterized them with respect to their structure, morphology, and stability. Using helium ion microscopy (HIM), we were able to visualize the integrity of the lipid 2D-nanomembranes spanning micrometer-sized voids under high-vacuum conditions. Atomic force microscopy (AFM) investigations under ambient conditions revealed formation of intact and robust pore-spanning 2D-nanomembranes up to 8 × 2 μm2in size. Analysis by attenuated total reflection–Fourier transform infrared spectroscopy (ATR-FTIR) verified a distinct reduction of signal at 2143 cm–1from diacetylene groups in the 2D-nanomembranes after UV-polymerization. Further high-resolution AFM investigations of unpolymerized lipid monolayers revealed a well-ordered two-dimensional network, when deposited on highly oriented pyrolytic graphite (HOPG). These structures were inhibited for polymerized adlayers. Structural models for the molecular arrangement of the adlayers are proposed and discussed.