Synthesis of molecularly imprinted polymers by photo-iniferter polymerization under visible light†
The easiest way to make polymers able to specifically recognize a target molecule consists of copolymerizing functional monomers and a cross-linker around a molecular template. This method affords a rigid material bearing high affinity binding sites, namely a synthetic receptor or antibody mimic, known as the “molecularly imprinted polymer” (MIP). MIPs find applications in many fields where a specific molecular recognition process is involved, and to suit their application there is a constant need for engineering their physical forms and synthetic methods, with photo-structuring being particularly attractive. Herein we report for the first time the use of a photo-iniferter precipitation polymerization for the synthesis of MIPs under low-power visible light. Microspheres imprinted with testosterone as model targets were synthesized under either blue or green light, and the living fragments on their surface were further used for chain extension with model poly-(ethylene glycol methacrylate phosphate) brushes by reversible addition–fragmentation chain transfer (RAFT) polymerization, demonstrating the versatility of this approach.