Short-term assessment of cadmium toxicity and uptake from different types of Cd-based Quantum Dots in the model plant Allium cepa L
Language English Country Netherlands Media print-electronic
Document type Journal Article
PubMed
29407734
DOI
10.1016/j.ecoenv.2018.01.044
PII: S0147-6513(18)30053-8
Knihovny.cz E-resources
- Keywords
- Allium cepa L., Bioaccumulation, Cadmium, Differential pulse voltammetry, Fluorescence microscopy, Phytotoxicity, Quantum dots,
- MeSH
- Adsorption MeSH
- Onions chemistry drug effects MeSH
- Microscopy, Fluorescence MeSH
- Plant Roots chemistry drug effects MeSH
- Quantum Dots analysis toxicity MeSH
- Cadmium Compounds analysis toxicity MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Cadmium Compounds MeSH
We report on the toxicity and bioaccumulation of three different types of Cd-based quantum dots (QDs), dispersed in aqueous medium, for a model plant Allium cepa L. It is believed that encapsulation of nanoparticles should reduce their toxicity and increase their stability in different environments; in this work we studied how QD encapsulation affects their phytotoxicity. Core, core/shell, and core/shell/shell QDs (CdTe, CdTe/ZnS, and CdTe/CdS/ZnS QDs capped by 2-mercaptopropionic acid) were tested and CdCl2 was used as a positive control. After 24-h and 72-h exposure, total Cd content (MCd) and bioaccumulation factors (BAFs) were determined in all parts of A. cepa plants (roots, bulb, shoot), and the total length of the root system was monitored as a toxicity end-point. Measurements of total Cd content versus free Cd2+ content (with Differential Pulse Voltammetry, DPV) in exposure media showed differences in chemical stability of the three QD types. Correspondingly, selected QDs showed different toxicity for A. cepa and different Cd bioaccumulation patterns. CdTe QDs were the most toxic; their effect was similar to CdCl2 due to the release of free Cd2+, which was confirmed by the DPV measurements. Plants exposed to CdTe QDs also bioaccumulated the most Cd among all QD exposure groups. CdTe/ZnS QDs showed no toxicity and very low bioaccumulation of Cd in A. cepa; the main source of measured Cd in the plants were QDs adsorbed on their roots, which was confirmed by fluorescence microscopy. On the contrary, CdTe/CdS/ZnS QD toxicity and bioaccumulation patterns were similar to those of CdTe QDs and pointed to unstable CdS/ZnS shells.
Central European Institute of Technology Masaryk University Kamenice 5 625 00 Brno Czech Republic
SEYENS Information Solutions and Education Ltd Krimska ulica 20 1000 Ljubljana Slovenia
References provided by Crossref.org
Time-Dependent Growth of Silica Shells on CdTe Quantum Dots
