Nanochemistry and Biotechnology

Phytotoxicity of colloidal solutions of stabilized and non-stabilized nanoparticles of essential metals and their oxides
Kovalenko M.S., Konotop Ye.O., Karpets L.-A.M., Smirnov O.Ye., Batsmanova L.M., Taran N.Yu.
Educational and Scientific Center «Institute of Biology and Medicine», Taras Shevchenko National University of Kyiv, 64/13 Volodymyrska str., Kyiv 01601, Ukraine
E-mail: mariia.s.kovalenko@gmail.com

The potential impact of nanoparticles (NPs) on plants requires thorough study, since data on their ecotoxicity is highly controversial. The direct toxicity of metal NPs and their oxides depends on the chemical composition of the bulk material, the physical characteristics of NPs, and /or the generation of reactive oxygen species in plant tissues. NPs of essential metals (Cu and Mn), which phytotoxicity is researched in present work, have already been widely used in crop production as antimicrobial agents (Cu, CuO NPs) or as alternative fertilizer to conventional salts (Mn NPs). However, searches for improving the physical and chemical properties of nanomaterials are still ongoing. The presence of stabilizing agents on the surface of NPs provides them new properties, which in turn predetermines the toxicity of nanomaterials. Therefore, the purpose of the present study was to compare the phytotoxicity of colloidal solutions of NPs of Mn, Cu and their oxides obtained in the absence and presence of stabilizer. The standard test system of Allium cepa (L.) for laboratory experiment was used. The toxicity of the solutions of NPs was evaluated according to the growth response of the onion roots, and the cytotoxicity was estimated due to the proliferative activity of the root meristem cells. Solutions of stabilized NPs were more toxic for A. cepa comparatively to non-stabilized one according to root growth and root formation. However, they appeared to be not cytotoxic, since the proliferative activity of root apical meristem was not significantly affected. It can be assumed that phytotoxicity of stabilized and non-stabilized nanoparticles of essential metals and their oxides depends on their properties according to which they affect different mechanisms of growth that remain unclear and require further research.