Magnetic And Luminescent Dual-functional SiO2 Beads Created Through Controlled Sol-gel Process
Volume 2, Issue 3, Page 195-199 | DOI: 10.5185/amlett.2011.1212
Bi-functional SiO2 beads; iron oxide magnetic nanoparticlels; semiconduductor nanocrystals; sol-gel synthesis
A controlled sol-gel approach was developed to encapsulate luminescent CdTe and magnetic Fe3O4 nanocrystals (NCs) into SiO2 beads. The preparation procedure included the preparation of SiO2-coated Fe3O4 NCs, the attachment of the CdTe NCs on the SiO2-coated Fe3O4 NCs, the assembly of the CdTe NCs-attached Fe3O4 NCs, and the growth of a SiO2 shell. To prevent the photoluminescence (PL) quenching, Fe3O4 NCs were coated with a thin SiO2 layer before encapsulating into SiO2 beads together with CdTe NCs. The CdTe NCs retained high PL efficiency (30 %) in dual functional SiO2 beads. These SiO2 beads also revealed superparamagnetic behavior. The result would be utilizable for further application because of their high PL efficiency and magnetic property. The strategy described here should give a useful enlightenment for the design and fabrication of multiple functional SiO2 beads. Copyright © 2011 VBRI press.