Preparation of magnetic microspheres functionalized by lanthanide oxides for selective isolation of bovine hemoglobin

The isolation and depletion of highly-abundant proteins and peptides is of vital importance for the screening and monitoring of biomarkers which are low stoichiometry in proteomics and protein-based biotechnologies. Here we have designed and synthesized a series of magnetic microspheres MnFe 2 O 4 @SiO 2 @  Lanthanide Oxides (La= Ce, Sm, Er, Tm, Yb) whose surface were functionalized by lanthanide oxides that could successfully isolate bovine hemoglobin (BHb), and MnFe 2 O 4 @SiO 2 @Er 2 O 3 microspheres were found to be most efficient in separating BHb with excellent selectivity and a binding capacity as high as 238.2 mg/g. The resulting microspheres demonstrated the favorable performance for isolation of BHb from bovine serum as confirmed by SDS-PAGE, which would open a promising strategy in the pretreatment of proteomic analysis.