Preparation and characterization of amino-silane modified superparamagnetic silica nanospheres

Magnetite nanoparticles were prepared by coprecipitation of Fe2+ and Fe3+ with NH4OH, and then, silica was coated on the surface of the magnetite nanoparticles to form well-dispersed magnetic silica nanospheres. The size of spheres was controlled by changing the ratio of SiO2 to Fe3O4. Amino-silane was covalently coupled to the surface of the magnetic silica nanospheres and activated by glutaraldehyde. The morphology and magnetic properties of magnetic silica nanospheres were examined by TEM and VSM. The nanospheres have an average size of 100-200 nm diameter and possess superparamagnetic characteristics. Powder X-ray diffraction measurements show the spinel structure for the magnetite particles coated by silica. By protein immobilization assay, it was proved that the amino-silane treated magnetic silica nanospheres could significantly improve the capacity of protein immobilization. (C) 2003 Published by Elsevier B.V.

[1]  Y. Uchida,et al.  Synthesis and properties of polymeric latex particles and their conjugates with human immunoglobulin G , 1978 .

[2]  H. Honda,et al.  PREPARATION OF FINE MAGNETIC PARTICLES AND APPLICATION FOR ENZYME IMMOBILIZATION , 1991 .

[3]  A. Kondo,et al.  Preparation of thermo-sensitive magnetic hydrogel microspheres and application to enzyme immobilization , 1997 .

[4]  E. Vulfson,et al.  The synthesis of sub-micron magnetic particles and their use for preparative purification of proteins. , 1998, Biotechnology and bioengineering.

[5]  Xiaohong Li,et al.  Synthesis of magnetic polymer microspheres and application for immobilization of proteinase of balillus sublitis , 1995 .

[6]  J. Guesdon,et al.  Magnetie solid phase enzyme-immunoassay. , 1977, Immunochemistry.

[7]  Arijit Bose,et al.  Cell Separation Using Protein-A-Coated Magnetic Nanoclusters , 1995 .

[8]  T. Matsunaga,et al.  Amino-silane modified superparamagnetic particles with surface-immobilized enzyme , 1991 .

[9]  Akihiko Kondo,et al.  Development and application of thermo-sensitive magnetic immunomicrospheres for antibody purification , 1994, Applied Microbiology and Biotechnology.

[10]  A. Kondo,et al.  Adsorption of model proteins with wide variation in molecular properties on colloidal particles , 1992 .

[11]  M. Shinkai,et al.  Antibody‐conjugated magnetoliposomes for targeting cancer cells and their application in hyperthermia , 1995, Biotechnology and applied biochemistry.

[12]  V. Goetz,et al.  A novel magnetic silica support for use in chromatographic and enzymatic bioprocessing , 1991, Biotechnology and bioengineering.