Synthesis and manipulation of multifunctional, fluorescent-magnetic nanoparticles for single molecule tracking

Gang Ruan*, Dhananjay Thakur, Sean Hawkins, Jessica O. Winter

*Corresponding author for this work

Research output: Chapter in Book or Report/Conference proceedingConference Proceedingpeer-review

3 Citations (Scopus)


Heterogeneous nanostructures that possess multiple properties as a result of their differing constituent materials have attracted significant interest in the last few years. In particular, fluorescent-magnetic nanostructures have potential applications in imaging, separations, and single molecule tracking as a result of their fluorescent and magnetic properties. Here we report the synthesis of fluorescent-magnetic nanocomposites composed of fluorescent semiconductor quantum dots or graphitic carbon nanoparticles and magnetic iron oxide nanoparticles. We have developed synthetic strategies using either micellular or polymer encapsulation, yielding composites from ~10 - 100s of nms. Composites maintain the fluorescent and magnetic properties of their constituent materials. These composites can be used for in vitro and in vivo imaging using fluorescent or magnetic (e.g., MRI) modalities. Additionally, we describe the manipulation of these composites using magnetic instrumentation. In particular, we have designed a magnetic needle that can be used to manipulate nanocomposites. Particles as small as 30 nm can be manipulated while simultaneous observed through their fluorescent property. Single particle status can be confirmed through quantum dot blinking, demonstrating the potential of these composites for single molecule tracking.

Original languageEnglish
Title of host publicationColloidal Quantum Dots for Biomedical Applications V
Publication statusPublished - 2010
Externally publishedYes
EventColloidal Quantum Dots for Biomedical Applications V - San Francisco, CA, United States
Duration: 23 Jan 201025 Jan 2010

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


ConferenceColloidal Quantum Dots for Biomedical Applications V
Country/TerritoryUnited States
CitySan Francisco, CA


  • Carbon nanoparticles
  • Iron oxide nanoparticles
  • Multifunctional nanoparticles
  • Quantum dots

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