Synthesis Of Silane Coupling Agents And Multifunctional Link Arms For The Modification Of Nanoparticles

Magnetic nanoparticles have been widely used in biomedical,environmental protection,magnetic resonance imaging and catalytic engineering and other fields.The modification of the surface of magnetic nanoparticles and the preparation of magnetic nanoparticles with stable magnetic properties,small particle size distribution,good biocompatibility and different functions are the research focus.In this paper,superparamagnetic ferric oxide magnetic nanoparticles were prepared by chemical coprecipitation method.Fe3O4@SiO2 magnetic nanoparticles were prepared by coating the surface of the magnetic iron oxide nanoparticles with tetraethyl orthosilicate.The silane coupling agent containing an aminooxy group,mercaptopyridyl group and alkynyl group is synthesized by chemical method.The surface modification of Fe3O4@Si02 magnetic nanoparticles by using silane coupling agents was used to prepare the Fe3O4@Si02@S-S-O-NH2,Fe3O4@SiO2@S-S-Py and Fe3O4@SiO2@S-S-C?CH functionalized magnetic nanoparticles.The magnetic properties,particle size,crystal form and functional groups of magnetic nanoparticles were characterized by XRD,TEM,FT-IR and hysteresis loops.The average diameter of the magnetic nanoparticles is between 40 nm;Infrared analysis shows that the surface of the particles contains oxygenamino,mercaptopyridy1 and alkynyl functional groups,has good magnetic properties.The prepared functionalized magnetic nanoparticles can be used for protein extraction and enrichment.Prepared multifunctionalized L-lysine.L-lysine as the frame of the multifunctional linker biotin,aminooxy,azido groups was successfully introduced on the L-lysine by ortho-protecting reaction on the lysine.The biotin fragment could have specific interaction with avidin,the introduced aminooxy group could have oxime ligation with aldehyde/keton,the introduced azido group could have click chemistry with alkynyl-containing compounds.The multifunctionalaized lysine could facilitate the protein conjugation and labeling.