A magnetically separable, highly stable enzyme system based on nanocomposites of enzymes and magnetic nanoparticles shipped in hierarchically ordered, mesocellular, mesoporous silica

The development of a magnetically separable and highly stable enzyme system, using nanoparticles and mesoporous silica, was investigated. Nanometer-scale composites of enzyme molecules and hierarchically ordered magnetite nanoparticles were immobilized via a ship-in-a-bottle approach, which used co-adsorption of enzymes and magnetite (Fe₃O₄) nanoparticles. The enzyme molecules were crosslinked via glutaraldehyde (GA) treatment resulting in the effective entrapment of neighboring magnetite nanoparticles. These nanocomposites, called M-CLEAs, were found magnetically separable, highly loaded with enzymes, stable under harsh conditions, resistant to proteolytic digestion, and recyclable for iterative use with negligible loss of enzyme activity. The ship-in-a-bottle approach can be expanded to many other enzymes and has applications in bioremediation and bioconversion.