Preparation of Magnetic Dendrimer and its Immobilization Effect on Laccase

Abstract

Free laccase is difficult to application. Thus magnetic dendrimer (MPG-x) grafted by PAMAM was constructed using amino-functionalized Fe3O4 as divergent nucleus in this study. Then two immobilized laccase were prepared by glutaraldehyde crosslinking and copper chelating adsorption, respectively. The results showed that the two immobilized laccases showed better stability than free laccase. Moreover, the activation of Cu2+ in the active center of laccase made MPG-2@Cu2+-Lac exhibit better stability. MPG-2@GA-Lac and MPG-2@Cu2+-Lac retained 74.4% and 108.1% of the initial free laccase activity, respectively. Compared with MPG-2@GA-Lac, MPG-2@Cu2+-Lac achieved better methyl orange removal over a wider pH and temperature range.

Keywords: magnetic nanoparticles, Polyaminoamide (PAMAM) dendrimers, immobilized laccase, MO removal