Fatemeh Mir Najafi Zadeh1, Deborah Ramsey 1, Shelli McAlpine 1, Fan Wang 2, Peter Reece2 and John Arron Stride 1 *


1. School of Chemistry, University of New South Wales, Sydney, NSW 2052,
2. School of Physics, University of New South Wales, Sydney, NSW 2052,



Semiconductor nanocrystals or quantum dots (QDs) have received a great deal of attention over the last decade due to their unique optical and physical properties, classifying them as potential tools for biological and medical applications1,2. However, there are some serious restrictions to the bioapplications of QDs such as water solubility, toxicity and photostability in biological environments for both in-vivo and in-vitro studies3. In this research, studies have focused on the preparation of highly luminescent, water soluble and photostable QDs of low toxicity that can then be potentially used in a biological context. First, water soluble CdSe(S) QDs, ZnSe(S) QDs and CdSe(S)/ZnO core/shell QDs were synthesized and characterized. Then, the cytotoxicity of as-prepared QDs was studied in the presence of two cell lines: HCT-116 cell line as cancer cells and WS1 cell line as normal cells. Finally, CdSe(S) QDs were linked to Donkey-anti mouse (H+L) (IgG) antibody Cy3 fluorophore to prepare a CdSe(S)-antibody conjugated compound that can be potentially used for diagnostic purposes. The obtained QDs exhibited high crystallinity, water solubility, low toxicity and photostability, as shown in Figure 1.

Figure 1: As -synthesized QDs under UV light (a): ZnSe(S) QDs (blue), CdSe(S)/ZnO QDs (green) and CdSe(S) QDs (three other orange compounds); CdSe(S) QDs in Presence of HCT-116 cells (b): QDs (green) and the cells (red); cytotoxicity of QDs (c).