Development of epitope-imprinted polydopamine magnetic nanoparticles for selective recognition of allergenic egg ovalbumin

In this study, epitope-imprinted polydopamine (PDA) magnetic nanoparticles (EIP-MNP) were developed for selective separation of allergenic ovalbumin (OVA). The imprinting process was conducted through the polymerization of dopamine in the presence of OVA IgE-binding epitope as the template. Molecularly imprinted PDA was self-assembled on the surface of silica-functionalized magnetic nanoparticles (MNP@SiO2). Key parameters including template concentration, pH of precursor solution, and rebinding time were examined to optimize the recognition capability of EIP-MNPs. The results suggested that EIP-MNPs had high affinity to OVA with an imprinting factor of 7.52. The developed EIP-MNPs also exhibited good selectivity against bovine serum albumin, human serum albumin, and lysozyme. The recovery percentage of OVA from wine samples ranged from 95.4 to 105.7%, with the RSD from 3.32 to 5.69%. The method can be easily modified to separate other allergenic proteins from foods.Graphical abstract