Preparation of Silica Nanomaterials Encapsulated with Europium Complex of Eu(DBM)₃phen for Fluorescence Detection

Large bored, twig-like mesoporous silica nanosphenes (abbrv. MSNs) containing Cl-functional group were prepared through the reaction of tetraethoxysilane and a azotizing reagent, Cl-functional group containing silane, taking CTAB and a short-chained fluorocarbon anionic surfactant (Capstone FS-66) as dual-templates. Fluorescent complex of Eu(DBM)₃phen, which was synthesized with EuCl₃·6H₂O, 1,10-phenanthroline hydrochloride and dibenzoylmenthane, was encased into the matrix MSNs, and the surface of bore channels of the MSNs were modified with polyethyleneimine to give a more effective embedding of Eu(DBM)₃phen into the bore channels. Furthermore, multilayer polymers were adsorbed on the surface of the nanospheres layer by layer through self-assembly, and then a layer of silica film was encapsulated onto the surface of the nano-spheres to for core-shell structures. Finally, the fluorescent nanospheres were reacted with 3-aminopropyl-triethoxysilane to have amino groups attached on the surfuce, for conjugating with biomolecules, such as anitbodies. The structure and properties of the final product of the nanospheres prepared was characterized by TEM, fluorescence spectrophotometry, FTIR, showing that the fluorescent nanospheres have bore diameters of about 230 nm, given fluorescence intensity of about 2 800 a.u. and bending vibration peak of amino group was observed at 1 543 cm^-1.