RAFT Controlled Synthesis of Biodegradable Polymer Brushes on Graphene for DNA Binding and Release

The preparation of biodegradable and positively charged graphene–polymer nanocomposite for DNA uptake and release is presented. A pyrene-terminated poly(2-(dimethylamino) ethyl acrylate) is firstly synthesized via reversible addition–fragmentation chain transfer (RAFT) polymerization, followed by the attachment onto the graphene surface via the π–π stacking interaction. The positively charged polymer brushes benefit the uptake of the negatively charged DNA fragment via static interaction and the built-in disulfide linkage between the polymer chain and graphene surface allows the biodegradable release of DNA in the presence of reducing agents. X-ray photoelectron spectroscopy manifests the binding of DNA molecules to the polymer chains and agarose gel electrophoresis confirms the release of DNA.