Synergetic effect of Ni2+ and 5-acrylamidobenzoboroxole functional groups anchoring on magnetic nanoparticles for enhanced immobilization of horseradish peroxidase

In this work, a novel Ni 2+ &AABOB bifunctional core–shell magnetic composite nanoparticles (MNPs), Fe 3 O 4 @p(AABOB-co-AIM-Ni 2+ ), were synthesized for the immobilization of horseradish peroxidase (HRP). Two kinds of interaction are simultaneously incorporated to improve the stability and reusability of immobilized HRP: one is the coordination between Ni 2+ and amide group in HRP, and the other is the interaction of the wulff-type boronic acid group with cis-diol-containing HRP which belongs to a type of glycoproteins. Accordingly, the proposed approach achieved high enrichment capacity (174.75 mg/g, protein/beads), and the activity of immobilized HRP still achieved 80% after reuse for 5 cycles. The degradation efficiency of phenol in the presence of immobilized HRP reached 93% within 10 min, which was significantly higher than that of free HRP only about 50% within 20 min. In addition, the immobilized HRP can be easily separated from the reaction solution by an external magnetic field.