3D single-molecule active real-time tracking (3D-SMART) is used to track diffusing polymer aggregates in solution. The tracking method uses a two-dimensional electro-optic deflector and a tunable acoustic gradient lens to generate a dynamically moving laser spot in three dimensions. This laser spot with the predefined 3D pattern creates an effective detection area of 1 μm ×1 μm ×4 μm, within which single molecules can be localized in real-time. The location of the fluorescently labeled polymer aggregates excited in the detection area is estimated based on the photon arrival time. 3D-SMART is capable of locking on to freely diffusing polymer particles in three dimensions for minutes at a time. With this method, diffusing polymer particles with radii ranging from 500 nm to 800 nm can be tracked individually to give the 3D trajectory and the real-time 3D image. Combining this tracking with traditional polymerization characterization techniques (e.g., gel permeation chromatography) provides a full suite of complementary polymer characterization tools.

Active feedback three-dimensional tracking of polymers in the solution phase

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.