ICON Web & News
Search Using OECD Database
Return to Previous Page
Addition or Correction
Adhesion of quantum dots-induced membrane damage of Escherichia coli
Link to Journal Abstract
The toxicity of CdTe QDs modified with three different ligands, namely mercaptopropionic acid (MPA), N-acetyl-l-cysteine (NAC), and glutathione (GSH), were investigated via microcalorimetric, spectroscopic, and microscopic methods. The three ligand-modified QDs have nearly identical hydrodynamic size. The results of the calorimetric experiments and optical density measurements indicate that the QDs inhibited the growth of Gram-negative Escherichia coli. The toxicity order of the three QDs is MPA-CdTe QDs > GSH-CdTe QDs > NAC-CdTe QDs. The inhibitory effects of the QDs, cadmium chloride (CdCl2), MPA, and the CdCl2 and MPA mixture on E. coli growth indicate that the toxicity mechanism of QDs may be related to their bacterial adhesion. When dispersed in the cell suspensions, QDs tend to have their high surface energy reduced through adsorption to the bacterial surface, as confirmed by transmission electron microscopy and inductively coupled plasma atomic emission spectroscopy results. Furthermore, the effect of QDs on the membrane fluidity and permeability was investigated. GSH-CdTe QDs have a greater effect on the membrane function of E. coli than those of MPA-CdTe and NAC-CdTe QDs. This result may be attributed to the stronger lipophilicity of GSH compared with those of MPA and NAC.
For this study, the toxicity of CdTe QDs modified with three different ligands, namely mercaptopropionic acid (MPA), N-acetyl-l-cysteine (NAC), and glutathione (GSH), were investigated via microcalorimetric, spectroscopic, and microscopic methods on Gram-negative Escherichia coli.
Peer Reviewed Journal Article
Exposure Or Hazard Target
Method Of Study
Risk Exposure Group
Journal of Colloid and Interface Science, 389(1): 61-70 (January 2013)
Journal of Colloid and Interface Science
Lai L, Lin C, Xiao CQ, Xu ZQ, Han XL, Fu L, Li DW, Mei P, Jiang FL, Guo QL, Liu Y
Last updated on January 9, 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