A polymerizable photoswitchable fluorophore for super-resolution imaging of polymer self-assembly and dynamics

While single-molecule super-resolution microscopy has been routinely used for visualizing nanostructures in life sciences, the application of this technique in polymer science is much more rare, especially for visualizing polymer dynamics in situ. A major constraint is from the lack of suitable fluorophore chemistry and simple strategies to label polymer chains. In this talk, we will discuss a functional diarylethene-based photoswitchable fluorophore, which can be directly copolymerized with standard monomers such as styrene and methyl methacrylate with no further post-coupling reactions or purifications needed. The attachment of fluorophores onto polymer chains enables super-resolution imaging of model polymer blend systems (PS/PMMA) with different nanostructures. As each individual fluorophore can switch between its bright and dark state many times, multiple time-lapse images can be acquired to observe the dynamic nanostructural evolution of polymer blends during solvent vapor annealing. With the advantages of a universal, simplified labelling strategy and the ability to visualize polymer assembly in situ, this fluorophore may promote the widespread use of super-resolution microscopy in the polymer community.