Characterization of Porous Materials by Fluorescence Correlation Spectroscopy Super-resolution Optical Fluctuation Imaging

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• 作者：Lydia Kisley ; Rachel Brunetti ; Lawrence J. Tauzin ; Bo Shuang ; Xiyu Yi ; Alec W. Kirkeminde ; Daniel A. Higgins ; Shimon Weiss ; Christy F. Landes
• 刊名：ACS Nano
• 出版年：2015
• 出版时间：September 22, 2015
• 年：2015
• 卷：9
• 期：9
• 页码：9158-9166
• 全文大小：581K
• ISSN：1936-086X

文摘

Porous materials such as cellular cytosol, hydrogels, and block copolymers have nanoscale features that determine macroscale properties. Characterizing the structure of nanopores is difficult with current techniques due to imaging, sample preparation, and computational challenges. We produce a super-resolution optical image that simultaneously characterizes the nanometer dimensions of and diffusion dynamics within porous structures by correlating stochastic fluctuations from diffusing fluorescent probes in the pores of the sample, dubbed here as 鈥渇luorescence correlation spectroscopy super-resolution optical fluctuation imaging鈥?or 鈥渇csSOFI鈥? Simulations demonstrate that structural features and diffusion properties can be accurately obtained at sub-diffraction-limited resolution. We apply our technique to image agarose hydrogels and aqueous lyotropic liquid crystal gels. The heterogeneous pore resolution is improved by up to a factor of 2, and diffusion coefficients are accurately obtained through our method compared to diffraction-limited fluorescence imaging and single-particle tracking. Moreover, fcsSOFI allows for rapid and high-throughput characterization of porous materials. fcsSOFI could be applied to soft porous environments such hydrogels, polymers, and membranes in addition to hard materials such as zeolites and mesoporous silica.