CdS nanoparticles have a great potential for application in chemical research, bioscience and medicine. The aim of this study was to develop an efficient and environmentally-friendly method of plant-based biosynthesis of CdS quantum dots using hairy root culture of Linaria maroccana L. By incubating Linaria root extract with inorganic cadmium sulfate and sodium sulfide we synthesized stable luminescent CdS nanocrystals with absorption peaks for UV-visible spectrometry at 362 nm, 398 nm and 464 nm, and luminescent peaks at 425, 462, 500 nm. Transmission electron microscopy of produced quantum dots revealed their spherical shape with a size predominantly from 5 to 7 nm. Electron diffraction pattern confirmed the wurtzite crystalline structure of synthesized cadmium sulfide quantum dots. These results describe the first successful attempt of quantum dots synthesis using plant extract. 81.07.Ta; 81.16.-c; 81.16.Rf

Magnetic nanoparticles (MNPs) were “green” synthesized from a FeCl₃/FeSO₄/CoCl₂ mixture using ethanolic extracts of Artemisia tilesii Ledeb ‘hairy’ roots. The effect of chemical composition and reducing power of ethanolic extracts on the morphology, size destribution and other features of obtained MNPs was evaluated. Depending on the extract properties, nanosized magnetic materials of spherical (8–11 nm), nanorod-like (15–24 nm) and cubic (14–24 nm) shapes were obtained via self-assembly. Microspherical MNPs composed of nanoclusters were observed when using extract of the control root line in the synthesis. Polyhedral magnetic nanoparticles with an average size of ~30 nm were formed using ‘hairy’ root ethanolic extract without any additive. Studied samples manifested excellent magnetic characteristics. Field-dependent magnetic measurements of most MNPs demonstrated a saturation magnetization of 42.0–72.9 emu/g with negligible coercivity (∼0.02–0.29 emu/g), indicating superparamagnetic behaviour only for solids with a magnetite phase. The synthesized MNPs were minimally aggregated and well-dispersed in aqueous medium, probably due to their stabilization by bioactive compounds in the initial extract. The nanoparticles were tested for magnetic solid-phase extraction of copper (Cu), cadmium (Cd) and arsenic (As) pollutants in aqueous solution, followed by ICP-OES analysis. The magnetic oxides, mainly magnetite, showed high adsorption capacity and effectively removed arsenic ions at pH 6.7. The maximum adsorption capacity was ~150 mg/g for As(III, V) on the selected MNPs with cubic morphology, which is higher than that of previously reported adsorbents. The best adsorption was achieved using Fe₃O₄-based nanomaterials with low crystallinity, non-spherical form and a large number of surface-localized organic molecules. The phytotoxicity of the obtained MNPs was estimated in vitro using lettuce and chicory as model plants. The obtained MNPs did not exhibit inhibitory activity. This work provides novel insights on the morphology of “green” synthesized magnetic nanoparticles that can be used for applications in adsorption technologies.

Transgenic lettuce plants ( Lactuca sativaL.) with genes coding the synthesis of tuberculous antigens were obtained using the Agrobacterium-mediated transformation procedure. Cotyledonary leaves of...

An efficient and rapid protocol for the establishment of Artemisia tilesii "hairy" root culture is reported. Leaf explants of aseptically growing plants were co-cultured with Agrobacterium rhizogenes A4 wild strain or A. rhizogenes carrying the plasmids with nptII and ifn-α 2b genes. Root formation on the explants started in 5-6 days after their cocultivation with bacterial suspension. Prolongation of explant cultivation time on the medium without cefotaxime led to stimulation of root growth. The effects of sucrose concentration as well as of the levels of synthetic indole-3-butyric acid (IBA) and native growth regulator Emistim(TM) on the stimulation of A.tilesii "hairy" root growth was studied. Maximum stimulating effect both for the control and transgenic roots was observed in case of root cultivation on the media supplemented with IBA - up to 7.95- and 9.1-fold biomass increase respectively. Cultivation on the medium with 10 μl/l Emistime(TM) has also led to the control roots growth stimulation (up to 2.75-fold). Emistime(TM) at 5 μl/l concentration led to 5.46-fold mass increase in only one "hairy" root line. Higher sucrose content (40 g/L) stimulated growth of two hairy root lines but had no effect on growth of the control roots.

This paper studies the biological activity of protein extracts of the Cichorium intybus L. and Lactuca sativa L. transgenic plants with the human interfero

Transgenic plants containing either ifn-α2b gene encoding human leukocytic interferon or esxA::fbpBΔ TMD genes encoding Mycobacterium tuberculosisantigens ESAT6 and Ag85B were regenerated from hairy...