Seed-mediated synthesis, properties and application of {gamma}-Fe{sub 2}O{sub 3}-CdSe magnetic quantum dots

Journal Article · Mon Aug 15 00:00:00 EDT 2011 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2011.05.043· OSTI ID:21580175

Lin, Alex W.H.; Ang, Chung Yen; Patra, Pranab K; Yu, Han; Hongwei, Gu ^[1]; Juraszek, Jean; Chiron, Hubert ^[2]; Papaefthymiou, Georgia C ^[3]

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1. Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore 138669 (Singapore)
2. Groupe de Physique des Materiaux, UMR 6634 CNRS, Universite de Rouen, Site Universitaire du Madrillet, Avenue de l'Universite, BP 12 76801 Saint Etienne du Rouvray Cedex (France)
3. Department of Physics, Villanova University, Villanova, PA 19085 (United States)

Seed-mediated growth of fluorescent CdSe quantum dots (QDs) around {gamma}-Fe{sub 2}O{sub 3} magnetic cores was performed at high temperature (300 deg. 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. - Graphical abstract: (a) HRTEM image of oleic acid capped MPs. The size of MPs ranges from 8 to 10 nm. (b) XRD pattern of {gamma}-Fe{sub 2}O{sub 3} MPs. Highlights: > The fabrication of MQDs through a seed-mediated approach has been demonstrated. > The formation and assembly of these bi-functional nanocomposites have been elucidated. > The MQDs exhibit superparamagnetism and tunable emissions characteristic of the components. > MQDs with thin silica coating were successfully employed in the labeling of cancer cell membranes.

• OSTI ID: 21580175
• Journal Information: Journal of Solid State Chemistry, Vol. 184, Issue 8; Other Information: DOI: 10.1016/j.jssc.2011.05.043; PII: S0022-4596(11)00292-1; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CADMIUM SELENIDES
CELL MEMBRANES
COERCIVE FORCE
COMPOSITE MATERIALS
FERRITES
FLUORESCENCE
IRON OXIDES
LIGHT SCATTERING
MAGNETIC CORES
MAGNETIC PROPERTIES
MAMMARY GLANDS
NEOPLASMS
OLEIC ACID
POLYETHYLENE GLYCOLS
QUANTUM DOTS
SUPERPARAMAGNETISM
SYNTHESIS
TEMPERATURE RANGE 0400-1000 K
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
ALCOHOLS
BODY
CADMIUM COMPOUNDS
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CHALCOGENIDES
COHERENT SCATTERING
DIFFRACTION
DISEASES
ELECTRON MICROSCOPY
EMISSION
FERRIMAGNETIC MATERIALS
GLANDS
GLYCOLS
HYDROXY COMPOUNDS
IRON COMPOUNDS
LUMINESCENCE
MAGNETIC MATERIALS
MAGNETIC STORAGE DEVICES
MAGNETISM
MATERIALS
MEMBRANES
MEMORY DEVICES
MICROSCOPY
MONOCARBOXYLIC ACIDS
NANOSTRUCTURES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
ORGANS
OXIDES
OXYGEN COMPOUNDS
PHOTON EMISSION
PHYSICAL PROPERTIES
POLYMERS
SCATTERING
SELENIDES
SELENIUM COMPOUNDS
TEMPERATURE RANGE
TRANSITION ELEMENT COMPOUNDS