Synthesis Of Multiple Core/Shell Nanostructures Encapsulated By Mesoporous SiO₂

We demonstrated the encapsulation of CdTe quantum dots and ZnO nanorods with a layer of mesoporous SiO₂ shell for the purpose of integrating dual-emission property into one common nanostructure.The morphology, structure, and optical properties were characterized by means of TEM, SEM, HRTEM, XPS, XRD, BET, SAXS, UV, and PL.The nanocomposites had ultrasensitive fluorescence response to metal ions. CdTe@SiO₂/FITC nanocomposites were synthesized by the encapsulation of CdTe QDs with SiO₂ shell, the modification of SiO₂ shell with APTS, and the connection of FITC. The nanocomposites were characterized by means of TEM, SEM, BET, SAXS, UV, and PL. The results showed that the products were monodispersed and uniform, and the biluminescent properties of the products would have a good prospect in detection.By modifying the surface of the silica shell with silane coupling agents and polymerizing temperature-responsive N-isopropylacrylamide(PNIPAm), we synthesized nanocomposites of Fe₃O₄@SiO₂/PNIPAm. The morphology, magnetism, and their application as the carrier were studied. It is found that the products were monodispersed and uniform; and the polymerization has little effect on the magnetism of the nanocomposites. But the improvement of the experimental conditions was still needed to impart the nanocomposites better carrier properties.As new type of structural and functional materials, the nanocomposites of CdTe/ZnO@SiO₂, CdTe@SiO₂ /FITC, and Fe₃O₄@SiO₂/PNIPAm would show a wide range of applications in optical, electrical, and magnetic fields.