Qiang Zhe, Shebek Kevin M, Irie Masahiro, Wang Muzhou
Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States.
Department of Chemistry and Research Center for Smart Molecules, Rikkyo University, Nishi-Ikebukuro 3-34-1, Toshimaku, Tokyo 171-8501, Japan.
ACS Macro Lett. 2018 Dec 18;7(12):1432-1437. doi: 10.1021/acsmacrolett.8b00686. Epub 2018 Nov 20.
Single-molecule super-resolution microscopy has become a standard imaging tool in the life sciences for visualizing nanostructures , but the application of this technique in polymer science is much less explored. A key bottleneck is the lack of fluorophores and simple covalent attachment strategies onto polymer chains. Here, we report a functional diarylethene-based photoswitchable fluorophore that can be directly incorporated into polymer backbones through copolymerization, which significantly streamlines the labeling strategy, with no further postcoupling reactions or purifications needed. The attachment of fluorophores onto selectively labeled polymers enables super-resolution imaging of a series of model polymer blend systems with different nanostructures and chemical compositions. As each individual fluorophore is able to switch several times on average between its bright and dark state, multiple time-lapse images can be acquired to observe the dynamic nanostructural evolution of polymer blends upon solvent vapor annealing. With this demonstration of a universal, simplified labeling strategy and the ability to image polymer assembly under native conditions, this reported fluorophore may promote the widespread use of super-resolution microscopy in the polymer community.
单分子超分辨率显微镜已成为生命科学中可视化纳米结构的标准成像工具，但该技术在聚合物科学中的应用却鲜有探索。一个关键瓶颈是缺乏荧光团以及将其简单共价连接到聚合物链上的策略。在此，我们报道了一种基于二芳基乙烯的功能性光开关荧光团，它可通过共聚直接并入聚合物主链，这显著简化了标记策略，无需进一步的后偶联反应或纯化。将荧光团连接到选择性标记的聚合物上，能够对一系列具有不同纳米结构和化学组成的模型聚合物共混体系进行超分辨率成像。由于每个荧光团平均能够在其亮态和暗态之间切换多次，因此可以采集多个延时图像来观察溶剂蒸汽退火后聚合物共混物的动态纳米结构演变。通过展示这种通用、简化的标记策略以及在自然条件下对聚合物组装体成像的能力，本文报道的荧光团可能会促进超分辨率显微镜在聚合物领域的广泛应用。
