(618a) Single-Molecule Fluorescence Imaging and Sequencing of Synthetic Polymers

Microscopic sequences of synthetic polymers are critical to polymer properties, but are generally unknown and unavailable from traditional characterizations. We achieved imaging of single synthetic polymers with single-monomer resolution and sequencing of synthetic copolymers for the first time. We reported a general approach, CREATS (a Coupled Reaction Toward Super-resolution-imaging) to render polymerization reactions fluorogenic and further to image it at the single-molecule level. We synthesized norbornene-based monomer, carrying a BODIPY-based pro-fluorescent sidechain. The uncaged product of the monomer emits green upon UV irradiation. In order to image and sequence copolymers, another two monomers were also designed and obtained, uncaged products of which show yellow and red emissions. We firstly imaged homo-polymerization of the monomer, observed representative fluorescence trajectory for polymerization and realized nanometer-level localization of the individual polymerized monomers with the single-monomer resolution. We then moved to sequence single copolymers using monomers whose uncaged products showed different emissions with the multi-color imaging. Our results indicate the tendency to forming block copolymers. We expect the CREATS approach could extend the applicability of single-molecule fluorescence imaging to polymer characterizations.