Facile synthesis of QD-anchored composite particles with magnetite cluster cores ({sup n}Fe{sub 3}O{sub 4}@SiO{sub 2}@QDs)
- Department of Chemical and Biochemical Engineering, Gachon University, San 65, Bokjeong-Dong, Sujeoung-Ku, Seongnam, Geonggi-Do 461-701 (Korea, Republic of)
Highlights: ► Triple layered Fe{sub 3}O{sub 4}/SiO{sub 2}/QDs were designed as fluorescent magnetic nanocomposites. ► Magnetite cluster-embedded silica exhibited strong and controllable magnetism. ► Effective conjugation between QDs and magnetic silica occurred at pH3. - Abstract: Magnetism-controlled fluorescent composite particles ({sup n}Fe{sub 3}O{sub 4}@SiO{sub 2}@QDs) were prepared as QD-anchored silica nanoparticles with magnetite cluster cores. First, citrate-capped magnetites (C-Fe{sub 3}O{sub 4}) were prepared by the co-precipitation method and subsequently complexed with 3-aminopropyl-trimethoxysilane (APTMS) at room temperature, consequently leading to the formation of magnetite clusters (A-{sup n}Fe{sub 3}O{sub 4}) with alkoxy terminated interfaces. The sol–gel reaction between A-{sup n}Fe{sub 3}O{sub 4} and tetraethoxysilane (TEOS) produced the core-shell {sup n}Fe{sub 3}O{sub 4}@SiO{sub 2}. The resulting core-shell particles exhibited superparamagnetic properties and controllable magnetism simply by adjusting the thickness of nonmagnetic silica layer. After then, amine-terminated {sup n}Fe{sub 3}O{sub 4}@SiO{sub 2} (NH{sub 2}–{sup n}Fe{sub 3}O{sub 4}@SiO{sub 2}) was conjugated with carboxy quantum dots (QDs) using an EDC coupling agent. The QD conjugation with NH{sub 2}–{sup n}Fe{sub 3}O{sub 4}@SiO{sub 2} of lower pH exhibited the higher photoluminescence (PL) intensity, and the resulting composite particles ({sup n}Fe{sub 3}O{sub 4}@SiO{sub 2}@QDs) can be a useful biomedical agent. This chemical strategy can be further applied to prepare the core-shell magnetic nanostructure with various oxide layers for specific applications.
- OSTI ID:
- 22341684
- Journal Information:
- Materials Research Bulletin, Vol. 48, Issue 6; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
- Country of Publication:
- United States
- Language:
- English
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