Seed-mediated synthesis, properties and application of γ-Fe 2O3-CdSe magnetic quantum dots

Alex W.H. Lin, Chung Yen Ang, Pranab K. Patra, Yu Han, Hongwei Gu, Jean Marie Le Breton*, Jean Juraszek, Hubert Chiron, Georgia C. Papaefthymiou, Subramanian Tamil Selvan, Jackie Y. Ying

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

Seed-mediated growth of fluorescent CdSe quantum dots (QDs) around γ-Fe2O3 magnetic cores was performed at high temperature (300 °C) in the presence of organic surfactants. Bi-functional magnetic quantum dots (MQDs) with tunable emission properties were successfully prepared. The as-synthesized MQDs were characterized by high-resolution transmission electron microscopy (HRTEM) and dynamic light scattering (DLS), which confirmed the assembly of heterodimers. When a longer growth period was employed, a homogeneous dispersion of QDs around a magnetic nanoparticle was obtained. The magnetic properties of these nanocomposites were examined. The MQDs were superparamagnetic with a saturation magnetization of 0.40 emu/g and a coercivity of 138 Oe at 5 K. To demonstrate their potential application in bio-labeling, these MQDs were coated with a thin silica shell, and functionalized with a polyethylene glycol (PEG) derivative. The functionalized MQDs were effectively used for the labeling of live cell membranes of 4T1 mouse breast cancer cells and HepG2 human liver cancer cells.

Original languageEnglish (US)
Pages (from-to)2150-2158
Number of pages9
JournalJournal of Solid State Chemistry
Volume184
Issue number8
DOIs
StatePublished - Aug 1 2011

Keywords

  • Magnetic quantum dots
  • Seed-mediated growth
  • Superparamagnetism

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

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