Molecularly imprinted hydrogels for the capture of the peptide hormone hepcidin were prepared by water-in-oil (w/o) suspension polymerization under mild conditions. Spherical and relatively uniformly sized gel beads were routinely obtained after optimization of the synthetic methodology. The polymers were analyzed by Fourier transform infrared spectroscopy, optical microscopy, and scanning electron microscopy. Although the imprinted materials exhibited higher affinity towards the epitope template (hepcidin N-terminus) than their corresponding blank polymers, the full-length target peptide was found strongly bound to all the hydrogels tested. However, by using whole fluorescent hepcidin as the print species, the imprinting effect was more pronounced. Moreover, bovine serum albumin did not bind to the poly N-isopropylacrylamide (PNIPAm)-based polymers. Thus, polymeric "sponges" for biomacromolecules with size-exclusion effect were developed, useful for peptide concentration, immobilization and/or purification from serum samples. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: F'olym Chem 48: 1721-1731, 2010