Multifunctional particles: Magnetic nanocrystals and gold nanorods coated with fluorescent dye-doped silica shells

Journal Article · Tue Jul 15 04:00:00 EDT 2008 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2008.05.002· OSTI ID:21128348

Heitsch, Andrew T; Smith, Danielle K; Patel, Reken N ^[1]; Ress, David ^[2]

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1. Department of Chemical Engineering, Texas Materials Institute, Center for Nano- and Molecular Science and Technology, University of Texas at Austin, Austin, TX 78712-1062 (United States)
2. Imaging Research Center, University of Texas at Austin, Austin, TX 78759-5316 (United States)

Multifunctional colloidal core-shell nanoparticles of magnetic nanocrystals (of iron oxide or FePt) or gold nanorods encapsulated in silica shells doped with the fluorescent dye, Tris(2,2'-bipyridyl)dichlororuthenium(II) hexahydrate (Rubpy) were synthesized. The as-prepared magnetic nanocrystals are initially hydrophobic and were coated with silica using a microemulsion approach, while the as-prepared gold nanorods are hydrophilic and were coated with silica using a Stoeber type of process. Each approach yielded monodisperse nanoparticles with uniform fluorescent dye-doped silica shells. These colloidal heterostructures have the potential to be used as dual-purpose tags-exhibiting a fluorescent signal that could be combined with either dark-field optical contrast (in the case of the gold nanorods), or enhanced contrast in magnetic resonance images (in the case of magnetic nanocrystal cores). The optical and magnetic properties of the fluorescent silica-coated gold nanorods and magnetic nanocrystals are reported. - Graphical abstract: Colloidal gold nanorods and iron platinum and iron oxide nanocrystals were encapsulated with fluorescent dye-doped silica shells using a generic coating strategy. These heterostructures are promising contrast agents for dual-mode medical imaging. Their optical and magnetic properties were studied and are reported here.

• OSTI ID: 21128348
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 7 Vol. 181; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
CONTRAST MEDIA
DOPED MATERIALS
GOLD
IRON ALLOYS
IRON OXIDES
MAGNETIC PROPERTIES
MAGNETIC RESONANCE
MICROEMULSIONS
NANOSTRUCTURES
NMR IMAGING
PARTICLES
PLATINUM ALLOYS
SILICA