Combined magnetic and chemical covalent immobilization of pectinase on composites membranes improves stability and activity

The idea of preparing the surface of Fe3O4 layer preadsorbed on the “spherical polyelectrolyte brush” via layer-by-layer self-assembly approach receives special relevance in enzyme technology. “Spherical polyelectrolyte brush” of core–shell structure were prepared by grafting poly(sodium 4-styrenesulphonate) (PSStNa) from SiO2 nanoparticles via the surface-initiated atom transfer radical polymerization strategy. The silica-coated (PEI/Fe3O4)n support presents a very simple, mild, and time-saving process for enzyme immobilization. The kinetics of a model reaction catalyzed by the immobilized pectinase was finally investigated by the Michaelis–Menten equation. These particles, premodified with the layer of magnetic nanoparticles to impart a magnetic property and subsequently coated with polyelectrolyte multilayer, were repeatedly used as catalysts following their rapid and easy separation with a magnet. Besides simplicity and versatility, the ease of enzyme regeneration constitutes an additional benefit of this approach.