Phytotoxicity of Ag nanoparticles prepared by biogenic and chemical methods

Abstract

Silver nanoparticles (Ag NPs) are now widely used as antibacterial and antifungal materials in different consumer products. We report here the preparation of Ag NPs by neem leaves extract (Azadirachta) reduction and trisodium citrate-sodium borohydride reduction methods, and study of their phytotoxicity. The nanoparticles were characterized by UV-Vis spectroscopy, FTIR, and atomic force microscopy (AFM) techniques. Both neem-coated and citrate-coated Ag NPs exhibit surface plasmon around 400 nm, and their average sizes measured by AFM are about 100 and 20 nm, respectively. Antibacterial and antifungal activities of these nanomaterials have been studied by simple pea seed germination and disk diffusion methods. It has been observed from the growth of root and shoot, citrate-coated Ag NPs significantly affect seedling growth, but neem-coated Ag NPs exhibit somehow mild toxicity toward germination process due to the nutrient supplements from neem. On the other hand, antifungal activity of neem-coated Ag NPs has been found much higher than that of citrate-coated Ag NPs due to the combined effects of antifungal activity of neem and Ag NPs. Present research primarily indicates a possible application of neem-coated Ag NPs as a potential fungicide.

Cascade Conversion of Cellobiose to Gluconic Acid: The Large Impact of the Small Modification of Electronic Interaction on the Performance of Au/TiO2 Bifunctional Catalysts

“…The colours of the samples are shown in Supporting material, Figure S5. Such a change in colour can be attributed to extended light adsorption in the visible region, [48,49] which can be the result of the presence of structural defects such as oxygen vacancies and/or interstitial Ti 3 + in the TiO 2 . [40] The catalysts were further characterised by DRUV-Vis absorbance spectra.…”

Green synthesis of silver nanoparticles mediated by traditionally used medicinal plants in Sudan

“…For example (1) less toxic and hazardous materials and environmentally benign solvents, (2) simple, rapid and cost effective, (3) consumes less energy and performs under moderate operation conditions, (4) combines the potency of both silver nanoparticles and plant active ingredients. In this respect, plant-mediated silver nanoparticles have been reported to possess more biological activities than nanoparticles synthesized by chemical methods [5].…”

Temperature‐Dependent Raman Study of Nanostructured and Multifunctional Materials

“…[1,2] The interpretation of these results is slightly modified here, in accordance with recent experimental and theoretical findings related to the variation of nanostructural properties of anatase with temperature. [26][27][28][29][30] The results of a detailed study of the most intense E g mode in the Raman spectra of anatase nanopowder synthesized by laserinduced pyrolysis, with crystallite size about 12.3 nm, are presented in the Figure 1. The spectra in the temperature range from 25 to 300 K were taken in closed cryostat coupled with Jobin Yvon U1000 macro-Raman system.…”

“…In this case PCM included not only the effects of phonon confinement and nonstoichiometry, but also the strain. Namely, recently published results have revealed that the strain in anatase particles varied with temperature [26,27,29,30] : at some medium-high temperatures, the strain could be released, but at high temperatures, close to the transformations from anatase to rutile phase, the strain could strengthen again. Also, in situ x-ray diffraction study of the anatase microstructure evolution as a function of temperature has confirmed that anatase nanoparticle size increased with temperature.…”