Fabrication of Yb³⁺-Immobilized Hydrophilic Phytic-Acid-Coated Magnetic Nanocomposites for the Selective Separation of Bovine Hemoglobin from Bovine Serum

In this work, Yb3+-immobilized hydrophilic phytic-acid-coated magnetic nanocomposites were prepared through a facile route and used to selectively separatrf bovine hemoglobin. Hydrophilic phytic acid (PA) was coated onto the magnetic Fe3O4-PEI via electrostatic interactions, followed by finally chelating with Yb3+ ions, which could produce specific protein binding sites at room temperature in water, and complex instrumentation was not necessary. The performance of as-prepared hybrids (Fe3O4-PEI-PA-Yb3+) was assessed by selectively isolating bovine hemoglobin (BHb). The obtained maximum binding capacity was 347.3 mg g–1. The retained BHb could be eluted under simple elution via using 0.1 M of Na2CO3, giving a recovery of 83%. Moreover, the generation of nanocomposites was demonstrated. In addition, the PA and PEI could improve the hydrophilicity of nanoparticles and further reduce the nonspecific adsorption. Therefore, such nanocomposites were successfully employed to selectively bind and separate BHb from bovine serum as verified by SDS-PAGE and MALDI-TOF MS analysis, providing a new perspective for the isolation of heme proteins in proteomics.