Dense covalent attachment of magnetic iron oxide nanoparticles onto silica particles using a diazonium salt chemistry approach

We demonstrate that the reaction of amino modified particles with tert-butylnitrite can provide diazonium surface functionality which itself is highly reactive with iron oxide nanoparticles in basic media. Using this strategy we synthesize a magnetic hybrid material with dense covalent attachment of magnetic iron oxide nanoparticles on the silica surface. This simple and versatile functionalization procedure has a wide variety of potential applications in surface science and materials research.