DNA–Polymer Conjugates by Photoinduced RAFT Polymerization

Conventional grafting-to approaches to DNA-polymer conjugates are often limited by low reaction yields due to the sterically hindered coupling of a presynthesized polymer to DNA. The grafting-from strategy, in contrast, allows one to directly graft polymers from an initiator that is covalently attached to DNA. Herein, we report blue-light-mediated reversible addition-fragmentation chain-transfer (Photo-RAFT) polymerization from two different RAFT agent-terminated DNA sequences using Eosin Y as the photocatalyst in combination with ascorbic acid. Three monomer families (methacrylates, acrylates and acrylamides) were successfully polymerized from DNA employing Photo-RAFT polymerization. We demonstrate that the length of the grown polymer chain can be varied by altering the monomer to DNA-initiator ratio, while the self-assembly features of the DNA strands were maintained. In summary, we describe a convenient, light-mediated approach toward DNA-polymer conjugates via the grafting-from approach.