Contaminated water with heavy metal ions is responsible for several health issues in humans, and methods of removing these heavy metal ions are often expensive or result in secondary pollutants. Zinc sulfide-based (ZnS) quantum dots provide an alternative method for detecting toxic heavy metal ions due to their tunable optical properties and surface chemistry. ZnS-based quantum dots were prepared via hot-injection of trisubstituted thioureas into zinc oleate, and the influence of electron-withdrawing versus electron-donating substituents on particle size and crystallinity was evaluated. Fluorescence quenching studies were conducted to evaluate the sensitivity of the QDs towards heavy metal ions. To transfer the QDs to an aqueous environment, the oleate ligands were exchanged for water-soluble ligands. The ligand binding was investigated using nuclear magnetic resonance spectroscopy.
Acknowledgements: This work was supported by Union College Undergraduate Research Office, Union College Faculty Research Fund, and The Community Foundation of the Greater Capital Region.