Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2018 May 30:153:23-31.
doi: 10.1016/j.ecoenv.2018.01.044. Epub 2018 Feb 2.

Short-term assessment of cadmium toxicity and uptake from different types of Cd-based Quantum Dots in the model plant Allium cepa L

Pavlína Modlitbová  1 , Pavel Pořízka  2 , Karel Novotný  3 , Jana Drbohlavová  2 , Ivana Chamradová  2 , Zdeněk Farka  3 , Helena Zlámalová-Gargošová  4 , Tea Romih  5 , Jozef Kaiser  2
Affiliations

Short-term assessment of cadmium toxicity and uptake from different types of Cd-based Quantum Dots in the model plant Allium cepa L

Pavlína Modlitbová et al. Ecotoxicol Environ Saf. .

Abstract

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.

Keywords: Allium cepa L.; Bioaccumulation; Cadmium; Differential pulse voltammetry; Fluorescence microscopy; Phytotoxicity; Quantum dots.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

Substances

LinkOut - more resources