Magnetic nanoparticles Fe3O4 were synthesized by the co-precipitation method. Magnetic nanoparticles were activated and modified with (3-aminopropyl) triethoxysilane (APTES) and glutaraldehyde (GA), respectively. Then, these nanoparticles were characterized by transmission electron microscope and Fourier transform infrared. Candida rugosa lipase (CRL) was successfully immobilized on GAMNPs by the chemical method via forming a covalent bond between a functional group on an enzyme protein molecule and a reactive group on the surface of solid support by chemical interaction. CRL-Fe3O4 displayed an elevate recovery rate of upward to 1348%, which was a 13-fold improvement in its free one. Compared to a free enzyme, the pH and thermal properties of the immobilized lipase were also increased. This study clearly indicates that GAMNPs could be deemed good support for the immobilization of enzymes
