Abstract
<jats:p>Radical polymerizations are among the most widely used polymer synthesis methods and have become versatile reactions for modifying living cells with bioorthogonal macromolecules and creating artificial cells. However, to follow and monitor these reactions, a fluorescence assay would be needed. Here, we introduce 3-acrylamide-7-(diethylamino)-coumarin (CAAm), a fluorogenic monomer that is initially non-fluorescent but strongly fluoresces upon polymerization. CAAm is copolymerized in small quantities with water-soluble monomers, resulting in a direct correlation between monomer conversion and fluorescence emission intensity. This allows the kinetics of reversible-deactivation radical polymerizations, such as conventional and enzyme-catalyzed atom transfer radical polymerizations (ATRP and bioATRP), to be followed by fluorescence spectroscopy. Reaction conditions for enzymatic polymerizations can be screened in 96-well plates. Moreover, CAAm reveals the localization of copolymers synthesized within artificial cells and bacterial cells. The latter resulted in fluorescence that persisted in a subset of cells after a 3 h regrowth period.</jats:p>