Size-dependent biological effects of copper nanopowders on mustard seedlings

Abstract

Correlation between the size of copper nanoparticles and effects they produce on white mustard seedlings were studied in the paper. Copper nanopowders with average particle sizes of 45 and 200 nm with concentrations of 0.01–1000 wt ppm of seeds were used to treat white mustard seeds. Nonlinear dose effects were displayed by copper nanopowders obtained by chemical synthesis with the particle size of 35-60 nm. For 45 nm nanoparticles the highest biological activity with regard to germinating energy, 3-day stem and root weight was registered at 5.0 wt ppm concentration, while for root length and weight of the 7-day stems the 1.0 wt ppm concentration had the most pronounced effect. Copper submicron powder with average particle size of 200 nm displayed some effect only after 7th day of the experiment at high concentrations (from 100 to 1000 wt ppm) according to the measurements of length and weight of the seedlings. The obtained results can be used in the development of copper nanoparticles-based preparations for pre-sowing treatment of seeds.