Solvothermal synthesis of FeCo nanoparticles for magneto-controllable biocatalysis

A facile and simple one-step solvothermal method has been developed to synthesize FeCo nanoparticles with well-controlled composition, desired morphology and high saturation magnetization, which exhibit component-dependent magnetic behaviors: the increase of Fe content leads to the increase of saturation magnetization and the decrease of coercivity. Furthermore, due to the availability of a coarse surface for the stable adsorption of targeted cargo, the high saturation magnetization for efficient control and directional separation from a reaction mixture by an external magnetic field, the as-prepared magnetic FeCo nanoparticles could work as a fuel-free magneto-controllable carrier to load biocatalytically-active cargo lipase for magneto-controllable and recyclable biocatalytic synthesis of lauryl laurate under an external magnetic field. By alternate positioning of the FeCo carrier with loaded cargo in and out of the substrate solution, the biocatalysis for esterification from lauric acid and lauryl alcohol to lauryl laurate could be switched between On and Off states.