Studies of Fe3O4-Chitosan Nanoparticles Prepared by Co-Precipitation Under the Magnetic Field for Lipase Immobilization

A simple method was introduced to prepare magnetic Fe3O4-chitosan nanoparticles by chemical precipitation with 0.45 T static Nd-Fe-B magnetic field via glutaraldehyde cross-linking reaction, and the nanoparticles were used to immobilize lipase. The influence of magnetic field on the properties of magnetic nanoparticles was studied by scanning electron microscope (SEM), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The results showed that when the magnetic nanoparticles were prepared under the magnetic field, no obvious difference of the crystal structure was found, meanwhile, the morphology varied from random sphere-like to rod-like structure and magnetic character such as saturation magnetization (Ms), remnant magnetization (Mr), coercivity (Hc) were significantly changed. Furthermore, the lipase immobilized with nanoparticles prepared under the magnetic field enhanced the activity, operational and storage stability compared with the control sample.