(393ao) The Immobilization of Carbonic Anhydrase (CA) with Magnetic Fe3O4 Materials Such As PVA-Fe3O4 Nanoparticles and Fe3O4-PVA Thin Films for a Biomimetic CO2 Sequestration

We have investigated the enzyme immobilized materials such as CA-PVA-Fe₃O₄ nanoparticles and CA-Fe₃O₄-PVA thin films, which were fabricated by an entrapment method and electrostatic interaction. The surface of PVA has hydroxyl groups to immobilize the enzyme, and positive charge of carbonic anhydrase may support the immobilization in the PVA matrix, which has a negative net charge.

     First, magnetic Fe₃O₄ nanoparticles were prepared by a co-precipitation method and poly vinyl alcohol was used to coat the Fe₃O₄ surface. Fe₃O₄ and PVA-Fe₃O₄ were characterized with FT-IR, TEM, SEM and XRD to prove an immobilization environment. DSC, PPMS, DLS, and Zeta-potential measurement were used to investigate CA immobilization.

     Second, CA-Fe₃O₄-PVA composite thin films were fabricated by a mixing-drying process. The fabricated PVA network on Fe₃O₄ nanoparticles provides advantages such as optical transparency, flexibility as well as easy-controlled concentrations, and magnetizations. They were characterized with XRD, DLS, TGA, and PPMS to study enzymatic materials, where fine magnetic nanoparticles and carbonic anhydrase are embedded in a series of Fe₃O₄-PVA thin films.

     Finally, the enzyme activity was conducted with 4-nitrophenyl propionate (4-NPP) as a substrate, to confirm immobilized enzyme/substrate reaction. The effect of immobilized carbonic anhydrase on CaCO₃ precipitation was studied for using magnetic nanoparticles, and thin films, in order to develop a biomimetic CO₂ sequestration.