Polymer-Assisted Hierarchically Bulky Imprinted Microparticles for Enhancing the Selective Enrichment of Proteins

The fabrication of tailor-made structural materials for the selective extraction of low-abundance biomacromolecules from biosamples is highly desirable. In this work, a novel type of hierarchically bulky imprinted polydopamine/CaCO₃ microparticles using polymers with different charges was applied to selectively enrich the target protein lysozyme (Lyz). By different polymers mediating, three-dimensional controllable macro- and mesoporous microparticles were prepared after removing the supporting material CaCO₃ and the template protein Lyz. In particular, poly(styrenesulfonate sodium) (PSS)-assisted hierarchical bulky imprinted microparticles (denoted as PSS-PDA-MIP) had the best adsorption capacity for Lyz. The maximum binding capacity of PSS-PDA-MIP particles for Lyz was 1203.4 mg g^-1, five times higher than its corresponding nonimprinted polymer (NIP) particles. The results also demonstrated that the selectivity of PSS-PDA-MIP microparticles for Lyz was effective with multiple protein mixtures, diluted egg whites, and spiked human blood serum, which can be attributed to the macroporous channels, the specific stereo cavities, and the assisted-polymer functional groups.