Ultrasound assisted reverse micelle efficient synthesis of new Ta-MOF@ Fe3O4 core/shell nanostructures as a novel candidate for lipase immobilization

Highlights: • A new magnetic Ta-MOF@Fe₃O₄ core/shell nanostructure was synthesized using ultrasound assisted reverse micelle method. • The stability test indicated that the enzyme loaded into these nanostructures had high stability. • The immobilized Km12 lipase showed considerably improved and remaining enzyme activities at high concentration of substrate compared free enzyme. - Abstract: In the present study, Ta-MOF@Fe₃O₄ core/shell nanostructures were synthesized in optimal conditions using the rapid, efficient, and novel ultrasound assisted reverse micelle method. FTIR, TGA/DTG, XRD, TEM, EDS and N₂ adsorption/desorption isotherms were conducted in order to obtain samples with desirable properties. Results showed that the synthesized products had the thermal stability of 200 °C, particle-size distribution of 38 nm and surface area of 740 m²/g. Also, the VSM test showed that these compounds have desirable magnetic properties which provide the opportunity for recovery. Based on these obtained properties, final products were used as a novel candidate for enzyme immobilization. Results of SEM images revealed that the Bacillus licheniformis Km12 lipase is efficiently loaded on the Ta-MOF@Fe₃O₄ core/shell substrate. The stability test indicated the high stability of the enzyme loaded into these nanostructures. The synthesis method and the results obtained from enzyme immobilization developed in this study can be a new strategy for various applications of these novel compounds in diverse biological fields.