Infectious diseases caused by pathogens are a health burden, but traditional pathogen identification methods are complex and time-consuming. In this work, we have developed well-defined, multifunctional copolymers with rhodamine B dye synthesized by atom transfer radical polymerization (ATRP) using fully oxygen-tolerant photoredox/copper dual catalysis. ATRP enabled the efficient synthesis of copolymers with multiple fluorescent dyes from a biotin-functionalized initiator. Biotinylated dye copolymers were conjugated to antibody (Ab) or cell-wall binding domain (CBD), resulting in a highly fluorescent polymeric dye-binder complex. We showed that the unique combination of multifunctional polymeric dyes and strain-specific Ab or CBD exhibited both enhanced fluorescence and target selectivity for bioimaging of Staphylococcus aureus by flow cytometry and confocal microscopy. The ATRP-derived polymeric dyes have the potential as biosensors for the detection of target DNA, protein, or bacteria, as well as bioimaging.

Conventional real-time monitoring of the polymerization is a laborious process that requires offline sampling and analysis. In this work, we introduce an advanced approach that combines Time-Resolved Diffusion NMR with 1H NMR for the simultaneous, in-situ tracking of both monomer conversion and molecular weight evolution. We successfully applied this method to monitor the photoinduced atom transfer radical polymerization (photo-ATRP) in real-time. Furthermore, by coupling the gamma model with dispersity-matched accumulation, we accurately determined the dispersity values of the resulting polymers. To make the method more accessible, we developed a user-friendly program that sets up the acquisition and simplifies real-time monitoring of photo-ATRP.