College of Resources and Environmental Sciences, China Agricultural University, Beijing 100091, China.
Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
Environ Pollut. 2015 Mar;198:8-14. doi: 10.1016/j.envpol.2014.12.017. Epub 2014 Dec 27.
Transformation is a critical factor that affects the fate and toxicity of manufactured nanoparticles (NPs) in the environment and living organisms. This paper aims to investigate the effect of phosphate on the transformation of CeO2 NPs in hydroponic plants. Cucumber seedlings were treated with 2000 mg/L CeO2 NPs in nutrient solutions with or without adding phosphate (+P or -P) for 3 weeks. Large quantities of needle-like CePO4 was found outside the epidermis in the +P group. While in the -P group, CePO4 only existed in the intercellular spaces and vacuole of root cells. X-ray absorption near edge spectroscopy (XANES) indicates that content and percentage of Ce-carboxylates in the shoots of -P group (418 mg/kg, 67.5%) were much higher than those in the +P group (30.1 mg/kg, 21%). The results suggest that phosphate might influence the transformation process of CeO2 NPs in plants and subsequently their ultimate fate in the ecosystem.
转化是影响人工纳米颗粒（NPs）在环境和生物体内命运和毒性的关键因素。本文旨在研究磷酸盐对水培植物中 CeO2 NPs 转化的影响。用含有或不含有磷酸盐（+P 或-P）的营养液处理黄瓜幼苗，浓度为 2000mg/L 的 CeO2 NPs，处理时间为 3 周。在+P 组中，大量针状的 CePO4 被发现存在于表皮之外。而在-P 组中，CePO4 仅存在于根细胞的细胞间隙和液泡中。X 射线吸收近边光谱（XANES）表明，-P 组（418mg/kg，67.5%）茎中 Ce-羧酸盐的含量和百分比远高于+P 组（30.1mg/kg，21%）。结果表明，磷酸盐可能会影响 CeO2 NPs 在植物中的转化过程，进而影响它们在生态系统中的最终归宿。
