ICON Web & News
Search Using OECD Database
Return to Previous Page
Addition or Correction
Thiol Antioxidant-Functionalized CdSe/ZnS Quantum Dots: Synthesis, Characterization, Cytotoxicity
Link to Journal Abstract
Nanotechnology is a growing industry with wide ranging applications in consumer product and technology development. In the biomedical field, nanoparticles are finding increasing use as imaging agents for biomolecular labeling and tumor targeting. The nanoparticle physiochemical properties must be tailored for the specific application. For example, nanoparticle chemical and physical stability in the biological milieu (no oxidation, aggregation, agglomeration or toxicity) are often required. Nanoparticles used for biomolecular fluorescent imaging should also have high quantum yield (QY). The aim of this paper is to examine the QY, stability, and cell toxicity of a series of positive, negative and neutral surface charge quantum dot (QD) nanoparticles. Simple protocols are described to prepare water soluble QDs by modifying the surface with thiol containing antioxidant ligands and polymers keeping the QD core/shell composition constant. The ligands used to produce negatively charged QDs include glutathione (GSH), N-acetyl-L-cysteine (NAC), dihydrolipoic acid (DHLA), tiopronin (TP), bucilliamine (BUC), and mercaptosuccinic acid (MSA). Ligands used to produce positively charged QDs include cysteamine (CYS) and polyethylenimine (PEI). Dithiothreitol (DTT) was used to produce neutral charged QDs. Commercially available nonaqueous octadecylamine (ODA) capped QDs served as the starting material. Our results suggest that QD uptake and cytotoxicity are both dependent on surface ligand coating composition. The negative charged GSH coated QDs show superior performance exhibiting low cytotoxicity, high stability, high QY and therefore are best suited for bioimaging applications. PEI coated QD also show superior performance exhibiting high QY and stability. However, they are considerably more cytotoxic due to their high positive charge which is an advantageous property that can be exploited for gene transfection and/or tumor targeting applications. The synthetic procedures described are straightforward and can be easily adapted in most laboratory settings.
The aim of this study was to examine the quatum yield, stability, and cell toxicity of a series of positive, negative and neutral surface charge quantum dot (QD) nanoparticles.
Peer Reviewed Journal Article
Exposure Or Hazard Target
Method Of Study
Risk Exposure Group
Journal of Biomedical Nanotechnology, 9(3): 382-392 (March 2013)
Journal of Biomedical Nanotechnology
Zheng H, Mortensen LJ, DeLouise LA
Last updated on May 2, 2013
This work is supported in part by the Nanoscale Science and Engineering Initiative of the National Science Foundation
under NSF Award Number EEC-0118007.
Why Join Us?
Mission and Strategy
Good Nano Guide
Nano EHS Research Needs
Current Practices Survey