Characterization and optimization of mesoporous magnetic nanoparticles for immobilization and enhanced performance of porcine pancreatic lipase

In this paper, Fe3O4 nanoparticles coated with mesoporous silica were prepared successfully, noted as Fe3O4 at the mobile composition of matter No. 41 (MCM-41). Also, Fe3O4 at MCM-41 was grafted by both 3-aminopropyltriethoxysilane (APTS) and 3-chloropropyltriethoxysilane (CPS), noted as Fe3O4 at MCM-41/APTS and Fe3O4 at MCM-41/CPS. The compounds were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, vibrating sample magnetometry, thermogravimetry and N2 adsorption/desorption. Then, the enzyme, porcine pancreas lipase (PPL), was immobilized onto these modified nanoparticles by covalent attachment, physical adsorption and cross-linking, noted as Fe3O4 at MCM-41/CPS-PPL, Fe3O4 at MCM-41-PPL and Fe3O4 at MCM-41/APTS-PPL, respectively. The results showed that Fe3O4 at MCM-41/CPS was the best nanomaterial for PPL immobilization, exhibiting enhanced immobilization efficiency (maximum 96%), maximum relative activity (up to 96%), high stability and reusability (83% 56 days and 86.7% ten cycles). Additionally, it offered some other advantages, such as easy recycling and reuse, complying with the trend of green chemistry. Therefore, Fe3O4 at MCM-41/CPS in combination with a relevant method can be proposed for commercial applications.