Synthesis and Characterization of Water-Soluble Nanoparticles John R. Renehan, Joseph A. Giesen, April D. Dale, Laura A. Logan, and Deon T. Miles Department of Chemistry

Acknowledgments• Faculty Research Grants

• Dr. Dongil Lee, Yonsei University

Project OverviewMonolayer-protected CdSe and ZnSe quantum dots (qdots) were synthesized in aqueous solutions. Several water-soluble thiols were used to protect the semiconducting core from surface oxidation and to improve the stability of the qdots. Differences in the spectral properties of the qdots were observed as a function of pH. Thiolated crown ether molecules were place-exchanged onto the surface of qdots, and the resulting changes in spectral properties were observed. Separation of the qdots by size was performed using HPLC. From fluorescence spectra of separated qdots, full-width at half-maximum (fwhm) values as small as 14 nm were observed, indicating the isolation of a narrow population size. Water-soluble, monolayer-protected Au25

nanoparticles were prepared via a place-exchange reaction with organic-soluble nanomaterials and water-soluble thiols. The gold nanomaterial was characterized using electrochemical techniques.

Water-Soluble Thiols and Qdot Synthesis1