The 20th annual Symposium will be held on Thursday, April 23, 2009.

Synthesis of Gold Core/Quantum Dot Shell Nanoparticles
Norris 100, 1:45 PM

Stacy  Capehart,   '09 11
   Major: Chemistry
   Hometown: Rochester, MI

Sponsor(s): Andrew French
Support: National Science Foundation Research Experience for Undergraduates; Boston University Department of Chemistry and the Photonics Center. This project was completed under the direction of Prof. Dr. Bjoern M. Reinhard in the Department of Chemistry and Photonics Center at Boston University in Boston, Massachusetts.

Abstract: 
Fluorescent organic dyes are popular probes for cellular imaging. These probes, however, have low photobleaching thresholds, poor photochemical stability, broad spectrum profiles, and narrow excitation spectra. An area of interest in cellular imaging involves utilizing nanoparticles. Of interest are CdSe/ZnS quantum dots (QDs) and gold nanoparticles (AuNPs). CdSe/ZnS QDs are semiconducting nanoparticles that have broad excitation spectra, a narrow spectral line width, and are brighter and more photostable than organic dyes. AuNPs are colloidal suspensions of gold particles that also have interesting chemical and electronic properties, such as surface plasmon resonances. The imaging properties of AuNPs are also based on light scattering, so they do not blink or bleach under continuous excitation. These two nanoparticles (CdSe/ZnS QDs and AuNPs) were combined via two synthetic methods to produce a composite AuNP-core/QD-shell nanoparticle with interesting optical properties. Both the distance between the gold-core and QD-shell as well as the emission of the QDs were varied to optimize the fluorescence intensity and photostability of the composite nanoparticle.

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