Preparation and characterization of stable Core/Shell Fe3O4@Au
decorated with amine group for immobilization of lipase by covalent
attachment
Abstract
The self-assembly approach was used for amine decoration of core/shell
Fe3O4@Au with 4-aminothiphenol. This structure was used for covalent
immobilization of lipase using a Ugi 4-component reaction. The amine
group on the structure and carboxylic group from lipase can react in the
Ugi reaction and a firm and stable covalent bond creates between enzyme
and support. The synthesized structure was fully characterized and its
activity was explored in different situations. The results displayed the
pH and temperature stability of immobilized lipase compared to free
lipase in a wide range of pH and temperature. Also after 60 days, it
showed excellent activity while residual activity for the free enzyme
was only 10%. The synthesized structure was conveniently separated
using an external magnetic field and reused 6 times without losing the
activity of the immobilized enzyme.