Improved performance of immobilized laccase on amine-functioned magnetic Fe 3 O 4 nanoparticles modified with polyethylenimine

Improving catalytic activity of laccase immobilized on the branched polymer chains of magnetic nanoparticles under alternating magnetic field

“…This could enhance the contact between immobilized laccase and substrate and accelerate the diffusion of products. In addition, the PEI also acted as a spacer‐arm to reduce steric hindrance . As for the other two immobilized laccases, the viscosity of PEI (10 000/60 000) increased, which may have caused mass transport problems during the catalytic reaction.…”

“…According to the methods reported previously, branched PEI of different molecular weights (Mn∼1200, Mn∼10 000, Mn∼60 000) were covalently modified on Fe 3 O 4 –NH 2 NPs using glutaraldehyde (GA) as reactive intermediate and the products obtained, Fe 3 O 4 –NH 2 –PEI (1200/10000/60000) NPs, were chelated with Cu 2+ to immobilize laccase separately. The amount of laccase immobilized on the NPs was measured by the Bradford protein assay method …”

“…In addition, the PEI also acted as a spacer-arm to reduce steric hindrance. 18 As for the other two immobilized laccases, the viscosity of PEI (10 000/ 60 000) increased, which may have caused mass transport problems during the catalytic reaction. Moreover, the long chain of functionalized PEI may easily entwined during the continuous change of movement direction caused by the alternating magnetic field.…”

Polyethyleneimine grafting and Cibacron Blue F3GA modifying poly(methylmethacrylate) magnetic microspheres for protein adsorption

“…First, polyethyleneimine possesses high cationic charge density at neutral pH, it is an ideal polymer for adsorbing protein with negative charge via electrostatic attraction. Second, the good hydrophilicity of PEI can make it highly flexible and stretch in water solution environment when it is grafted on carriers . Therefore, it is significant to investigate the effect of PEI on Cibacron Blue modification and protein adsorption.…”

“…Second, the good hydrophilicity of PEI can make it highly flexible and stretch in water solution environment when it is grafted on carriers. 21 Therefore, it is significant to investigate the effect of PEI on Cibacron Blue modification and protein adsorption. In this paper, poly(methylemethacrylate) (PMMA) magnetic microspheres were prepared via suspension polymerization and hydrolyzed to produce carboxyl group.…”