Preparation of Fe3O4 magnetic nanomaterials for the enrichment of phosvitin phosphopeptides

Phosvitin phosphopeptides (PPP) have a high ability to chelate mineral ions and promote calcium absorption. In this study, The Fe3O4 nanospheres were first synthesized by hydrothermal method, then the three magnetic nanoparticles (Fe3O4@PDA@PMAA@PAMAM, Fe3O4@PDA@Ce4+, and Fe3O4@PDA@TiO2) were obtained by layer modification on their surfaces, respectively. The magnetic nanoparticles were characterized by TEM, XRD, VSM, and Zeta potential. TEM analysis revealed that the nanoparticles were spherical and regular in shape. XRD diffraction analysis showed that the modified nanoparticles have a complete crystal structure. Meanwhile, PAMAM, Ce4+, TiO2, and other groups have been successfully modified on the nanoparticles. VSM hysteresis regression line results revealed that the magnetic nanoparticles are superparamagnetic. The three kinds of magnetic nanoparticles still maintained excellent enrichment performance after five times of repeated use. Fe3O4@PDA@TiO2 has the best enrichment performance (167 mg g−1). The N/P ratio of the enriched PPP decreased from 1.36 to 0.98, which also showed that it had excellent PPP enrichment performance. Therefore, the modified magnetic nanoparticles could be an optimal PPP enrichment and purification material.