Amyloid-mediated platform for open-air surface-initiated atom transfer radical polymerization

Surface-initiated atom transfer radical polymerization (SI-ATRP) is a powerful technique for fabricating polymer brushes with precise molecular control, yet its practical deployment is hindered by oxygen susceptibility, catalyst residue, sluggish reaction kinetics and substrate-dependent initiator immobilization. Here, we introduce an interfacial concentration-assisted grafting (ICG) strategy based on an amyloid-like adhesive nanofilm of phase-transitioned lysozyme (PTL). The PTL layer enables universal initiator immobilization via a simple one-pot aqueous process on virtually any substrate, eliminating complex surface chemistry. Crucially, the PTL film adsorbs and concentrates monomer and Cu⁺/ligand catalyst at the interface, creating a localized high-reactivity zone that accelerates SI-ATRP kinetics. This enables rapid growth of polymer brushes in bulk solutions, where monomer and catalyst concentrations are an order of magnitude lower than those used in conventional systems and permits polymerization under open-air conditions. We demonstrate the versatility of this approach by synthesizing diverse functional polymer brushes from zwitterionic, cationic, anionic, and nonpolar monomers. This strategy simultaneously simplifies initiator anchoring, reduces resource usage, and enhances oxygen tolerance, significantly improving the practicality and scalability of SI-ATRP for surface modification applications.