| abstract |
The present invention is based on the discovery that the present invention is predominantly in the form of discrete, essentially spherical discrete particles, wherein the core consists essentially of one or more magnetic iron oxides, the shell is comprised of substantially dense amorphous silicon dioxide, Shell particles having an average diameter d 50 of 2 < d 50 < 10 μm. The iron oxide content of the particles is 83 to 92% by weight, the silicon dioxide content is 5 to 15% by weight, and the carbon content is 0.5 to 3% by weight. Amino or epoxy groups as part of the structural unit -OSi- alkyl -X, X is NH 2 or an epoxy, alkyl is a C 2 -C 8. The concentration of amino group or epoxy group is 30 μmol / g (particle) or more. The particles are used to immobilize the enzyme. |