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

Title Short-term assessment of cadmium toxicity and uptake from different types of Cd-based Quantum Dots in the model plant Allium cepa L.
Authors P. Modlitbová; P. Po?ízka; K. Novotný; J. Drbohlavová; I. Chamradová; Z. Farka; H. Zlámalová-Gargo?ová; T. Romih; J. Kaiser
Journal Ecotoxicol Environ Saf
DOI 10.1016/j.ecoenv.2018.01.044
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 CdClwas used as a positive control. After 24-h and 72-h exposure, total Cd content (M) 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 Cdcontent (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 CdCldue to the release of free Cd, 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.

Citation P. Modlitbová; P. Po?ízka; K. Novotný; J. Drbohlavová; I. Chamradová; Z. Farka; H. Zlámalová-Gargo?ová; T. Romih; J. Kaiser.Short-term assessment of cadmium toxicity and uptake from different types of Cd-based Quantum Dots in the model plant Allium cepa L.. Ecotoxicol Environ Saf. 2018;153:2331. doi:10.1016/j.ecoenv.2018.01.044

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Cadmium

See more Cadmium products. Cadmium (atomic symbol: Cd, atomic number: 48) is a Block D, Group 12, Period 5 element with an atomic weight of 112.411. Cadmium Bohr ModelThe number of electrons in each of Cadmium's shells is 2, 8, 18, 18, 2 and its electron configuration is [Kr]4d10 5s2. The cadmium atom has a radius of 151 pm and a Van der Waals radius of 230 pm. Cadmium was discovered and first isolated by Karl Samuel Leberecht Hermann and Friedrich Stromeyer in 1817. In its elemental form, cadmium has a silvery bluish gray metallic appearance. Cadmium makes up about 0.1 ppm of the earth's crust. Elemental CadmiumNo significant deposits of cadmium containing ores are known, however, it is sometimes found in its metallic form. It is a common impurity in zinc ores and is isolated during the production of zinc. Cadmium is a key component in battery production and particular pigments and coatings due to its distinct yellow color. Cadmium oxide is used in phosphors for television picture tubes. The name Cadmium originates from the Latin word 'cadmia' and the Greek word 'kadmeia'.

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