Lipase Functionalization of Silica-coated Biotemplated and Nonbiotemplated Magnetic Nanoparticles

Abstract

In this study, functionalized magnetic nanoparticles (MNPs) were prepared by the graft polymerization of tetraethyl orthosilicate and aminopropyltrimethoxysilane onto the surface of MNPs modified by biomineralization, followed by immobilization of an enzyme via chemisorption. The phases of the resulting powders were determined by several techniques. Kinetic parameters of the enzymatic reaction were determined by examining liquid crystal droplets by polarized light microscopy. The resultant nanoparticles and composites were characterized by transmission electron microscopy; enzymatic activities of the composites prepared by chemical synthesis or biological synthesis were compared with activity of the free enzyme. The results indicated that the enzyme was effectively immobilized on the surface of the magnetite (Fe3O4) nanoparticles and that the composites remained dispersive and superparamagnetic. The immobilized enzyme showed excellent biological activity and was not affected by the immobilization on nanoparticles.