Toxicological effects of different-sized Co-Fe (CoFe2O4) nanoparticles on Lepidium sativum L.: towards better understanding of nanophytotoxicity.

Abstract

Due to their widespread therapeutic and agricultural applicability and usefulness in removing metals and metalloids from water, cobalt ferrite nanoparticles (NPs) are currently receiving increasing attention from researchers. However, their potential phytotoxicity is still poorly understood. Thus, the aim of the current study was to assess the effects of synthesized cobalt ferrite (CoFe2O4) NPs on biological (morphological, physiological, and biochemical) parameters of edible plant garden-cress (Lepidium sativum L.), depending on particle size and concentrations. In this study, physical characteristics of cobalt ferrite NPs were determined. Increased total content of Co and Fe in L. sativum tissues and their transfer from roots to above-ground parts of seedlings, which depended on the size of NP (15 < 5 < 1.65 nm), indicated that plants had been exposed to Co ferrite NPs. The relative growth of roots, biomass of roots and above-ground parts of seedlings, amounts of chlorophylls a and b, carotenoids, and malondialdehyde (MDA) were determined. The dependence of the tested garden-cress parameters on the size and concentrations of NPs was revealed. Our data showed that the content of MDA in test plants in some cases increased up to 2.5 folds in comparison to control. The increase of the content of chlorophyll b pigment and MDA in test plants is an appropriate indicator of the impact of cobalt ferrite NPs. The findings of our study into toxicological effects of Co-Fe (CoFe2O4) NPs on L. sativum are expected to deepen the knowledge of the nanophytotoxicity of ferromagnetic NPs and their potential application in biomedicine and agriculture.