Initiator-free synthesis of molecularly imprinted polymers by polymerization of self-initiated monomers

- Molecularly imprinted polymers (MIPs) are synthesised without initiators.
- Self-initiated monomers are used for MIP synthesis.
- The yield of polymerization is high even at high monomer dilutions.
- Binding specificity and selectivity are similar to initiator-based MIPs.
- 'Greener' MIPs are produced as one toxic ingredient is eliminated.

Molecularly imprinted polymers (MIPs) are tailor-made synthetic materials with binding affinities and specificities comparable to those of antibodies and enzymes. These 'plastic' antibodies are composed of two or more types of monomers, and are generally synthesized by free radical polymerization. Polymerization is initiated by reactive radicals generated by the thermal or photo homolysis of a chemical bond on an initiator. Here, we show through several examples, that MIPs can be synthesized, without adding any initiator by using at least one monomer in the precursor mixture that can be photo or thermally polymerized by self-initiation. The binding characteristics as well as the size and morphology of the MIPs were examined. Remarkably, even at high monomer dilutions prevailing during precipitation polymerization, the yield of polymerization was high but above all, the MIPs were very specific and selective for their target molecule, indicating the creation of high-fidelity imprinted sites.