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生态毒理学报 2012
Detection of Reactive Oxygen Species Induced by Cadmium Tellurium Quantum Dots
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Abstract:
With the extensive application of quantum dots (QDs) in biomarker and bioimaging, the amount of human exposure to QDs increases, so the exploration of the mechanism of their biological toxicity is of significant concern. The generation of ROS (reactive oxygen species) induced by QDs is accepted to act as a mechanism to produce toxicity. To investigate the relationship between the toxicity of QDs and the production of ROS, cadmium-telluride QDs (CdTe QDs and CdTe/ZnS QDs) were selected, and the type and intensity of ROS were detected using electron paramagnetic resonance (EPR) when adding various concentrations of CdTe QDs or CdTe/ZnS QDs in the cell-free system. The promotive effect of CdTe QDs or CdTe/ZnS QDs on the production of superoxide anion (·O2-) and hydroxyl free radicals (·OH) was studied by EPR, ultraviolet and fluorescence spectrophotometer. Results showed that CdTe QDs could induce the production of ·O2-. The generation of ·OH and ·O2- could be obviously promoted by CdTe QDs and CdTe/ZnS QDs. The intensity of ·OH (or ·O2-) and the dose of QDs showed a clear dose-effect relationship. It was indicated that QDs could induce and promote the production of ROS. The inducing and promoting effect was dependent on the structure of QDs.