Effects of CuO nanoparticles on Lemna minor.

Lin Lin,Guanling Song,Rulin Ma,Yuan Gao,Lati Mu,Zhiwei Zhang,Wenhua Hou,Haixia Wang,Qiang Niu,Yan Wang

doi:10.1186/s40529-016-0118-x

Abstract

BackgroundCopper dioxide nanoparticles (NPs), which is a kind of important and widely used metal oxide NP, eventually reaches a water body through wastewater and urban runoff. Ecotoxicological studies of this kind of NPs effects on hydrophyte are very limited at present. Lemna minor was exposed to media with different concentrations of CuO NPs, bulk CuO, and two times concentration of Cu2+ released from CuO NPs in culture media. The changes in plant growth, chlorophyll content, antioxidant defense enzyme activities [i.e., peroxidase (POD), catalase (CAT), superoxide dismutase (SOD) activities], and malondialdehyde (MDA) content were measured in the present study. The particle size of CuO NPs and the zeta potential of CuO NPs and bulk CuO in the culture media were also analyzed to complementally evaluate their toxicity on duckweed.ResultResults showed that CuO NPs inhibited the plant growth at lower concentration than bulk CuO. L. minor roots were easily broken in CuO NPs media under the experimental condition, and the inhibition occurred only partly because CuO NPs released Cu2+ in the culture media. The POD, SOD, and CAT activities of L. minor increased when the plants were exposed to CuO NPs, bulk CuO NPs and two times the concentration of Cu2+ released from CuO NPs in culture media, but the increase of these enzymes were the highest in CuO NPs media among the three kinds of materials. The MDA content was significantly increased compared with that of the control from 50 mg L−1 CuO NP concentration in culture media.ConclusionCuO NPs has more toxicity on L. minor compared with that of bulk CuO, and the inhibition occurred only partly because released Cu2+ in the culture media. The plant accumulated more reactive oxygen species in the CuO NP media than in the same concentration of bulk CuO. The plant cell encountered serious damage when the CuO NP concentration reached 50 mg L−1 in culture media. The toxicology of CuO NP on hydrophytes must be considered because that hydrophytes are the basic of aquatic ecosystem.

Highlights

Copper dioxide nanoparticles (NPs), which is a kind of important and widely used metal oxide NP, eventually reaches a water body through wastewater and urban runoff
CuO NPs, with the purity is greater than 99.5 %, particle diameter is 40 nm and a surface area is 25–40 m2 g−1.The purity of bulk CuO is more than 99.9 %, particle diameter is 10 μm
Copper dioxide NPs aggregated in culture media

Summary

Introduction

Copper dioxide nanoparticles (NPs), which is a kind of important and widely used metal oxide NP, eventually reaches a water body through wastewater and urban runoff Ecotoxicological studies of this kind of NPs effects on hydrophyte are very limited at present. CuO NPs, an important kind of metal oxide NPs, are used in catalysis, gas sensors, solar energy conversion, high-temperature superconductors, and fieldemission emitters (Chowdhuri et al 2004; Yin et al 2005; Dar et al 2008; Jammi et al 2009) With such large-scale applications, CuO NPs will inevitably reach bodies of water through waste water and urban runoff. The toxicity study of CuO NPs on aquatic organisms has drawn considerable attention

Methods

Results

Conclusion