Ecotoxicity of halloysite nanotubes supported palladium nanoparticles on Raphanus sativus L.
Halloysite nanotubes (HNTs) are natural nanomaterials, biocompatible and available in large amounts at low prices. They are emerging nanomaterials with appealing perspectives for application like support for metal nanoparticles (NPs). Potential environmental impacts of NPs can be understood taking into consideration phytotoxicity. Current research focuses on HNTs application in cell or animal models, while their use in plants is limited so that their ecotoxicological impact is poorly documented. Up to date there are no studies on phytotoxic effects of functionalized halloysite (f‐HNTs). To develop a quantitative risk assessment model for predicting the potential impact of halloysite nanotubes supported palladium nanoparticles (HNT‐PdNPs) on plant life, we investigated their effect on seed germination, seedling development and mitotic division on root tip cells of two lots of Raphanus sativus L. with different vigour. The results evidenced that exposure to 1500 mg/L of HNT, f‐HNTs and HNT‐PdNPs had no significant influence on germination, seedling development, xylem differentiation and mitotic index of both lots. Cytogenetical analyses revealed that treatments with f‐HNT significantly increased the number of aberrations in low vigour seeds. Our results suggested that low vigour seeds represent a model of stress test useful to monitor the effects of NPs. Moreover this work offers scientific sustain for the use of halloysite for environmental purposes, supporting biological safety of the HNT‐PdNPs nanomaterial. This article is protected by copyright. All rights reserved