ABSTRACT
22Nanoparticles are submicron moieties with at least one dimension that is less than 100 nm. They exhibit certain novel physical and chemical properties that are distinct from the characteristics of their bulk counterparts. Fabrication of nanostructured materials such as metal nanoparticles, nanofibers, nanotubes, nanosheets, and nanocomposites for biological applications has evoked great interest in researchers around the globe. During the past few years, a significant number of reports have been published on exploring the potential of nanoparticles as carriers for enzymes. The large surface area to volume ratio of nanoparticles is one of the most advantageous characteristics over conventional materials used in immobilization and thus they offer high enzyme loading during the immobilization process. Enzymes immobilized onto nanoparticles also exhibit higher stability in a wide range of temperature and pH, compared to free enzymes. In recent years, magnetic nanoparticles particularly iron oxides (magnetite, Fe3O4 and maghemite, y-Fe2O3) have received significant importance due to their strong magnetic properties, chemical stability, and decreased toxicity. They find broad spectrum of biological applications such as contrast agents in magnetic resonance imaging (MRI), separation of biomolecules or cells, agents for drug delivery, tumor diagnosis, tissue engineering, in hyperthermia therapy, etc. Surface functionalized magnetic iron oxide nanoparticles serve as excellent candidates for immobilization of lipase enzyme as their magnetic property facilitates easy and effective recovery of the enzyme bound particles by the application of a magnetic field. This review focuses on the synthesis, surface functionalization, and immobilization of lipase enzyme on magnetic nanoparticles and the application of immobilized enzyme in biodiesel production.
