A self-assembled polydopamine film on the surface of magnetic nanoparticles for specific capture of protein

In this study, we report a facile method for the preparation of core-shell magnetic molecularly imprinted polymers (MIPs) for protein recognition. Uniform carboxyl group functionalized Fe3O4 nanoparticles (NPs) were synthesized using a solvothermal method. Magnetic MIPs were synthesized by self-polymerization of dopamine in the presence of template protein on the surface of the Fe3O4 NPs. A thin layer of polydopamine can be coated on Fe3O4 NPs via dopamine self-polymerization and the imprinted polydopamine shells can be controlled by the mass ratio of Fe3O4 NPs and dopamine. More importantly, there is a critical value of polydopamine shell thickness for the maximum rebinding capacity. The as-prepared lysozyme-imprinted Fe3O4@polydopamine NPs show high binding capacity and acceptable specific recognition behavior towards template proteins. This method provides the possibility for the separation and enrichment of abundant proteins in proteomic analysis.