Facile, high efficiency immobilization of lipase enzyme on magnetic iron oxide nanoparticles via a biomimetic coating

Background: Immobilization of lipase on appropriate solid supports is one way to improve their stability and activity, and can be reused for large scale applications. A sample, cost-effective and high loading capacity method is still challenging. Results: A facile method of lipase immobilization was developed in this study, by the use of polydopamine coated magnetic nanoparticles (PD-MNPs). Under optimal conditions, 73.9% of the available lipase was immobilized on PD-MNPs, yielding a lipase loading capacity as high as 429 mg/g. Enzyme assays revealed that lipase immobilized on PD-MNPs displayed enhanced pH and thermal stability compared to free lipase. Furthermore, lipase immobilized on PD-MNPs was easily isolated from the reaction medium by magnetic separation and retained more than 70% of initial activity after 21 repeated cycles of enzyme reaction followed by magnetic separation. Conclusions: Immobilization of enzyme onto magnetic iron oxide nanoparticles via poly-dopamine film is economical, facile and efficient.