Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, 14040-900, Brazil.
Environ Sci Pollut Res Int. 2021 Apr;28(13):16720-16733. doi: 10.1007/s11356-020-11862-1. Epub 2021 Jan 4.
The use of silver nanoparticles (AgNPs) in commercial products has increased due to their antibacterial properties and their impacts on the environment must be investigated. This scenario has motivated the conduction of this study, which relates different factors that affect the toxicity of AgNPs to the aquatic plant Lemna minor such as size, accumulation, concentration, and dissolution of AgNPs. To this end, synthesized AgNPs measuring 30, 85, and 110 nm were added into the culture medium to observe toxicity for 30 days. The mapping by SEM showed that the smallest AgNPs can translocate from roots to leaves due to its mobility and internalization. As predicted by the Ostwald equation, the solubility for 30-nm AgNPs increased almost 3 times at the end of 30 days, while for 85 and 110 nm size nanoparticles, after 7 days, the solubility decreased due to "Ostwald ripening" process. Plant mortality was assessed and, after 1 month, the size of 30 nm was the most toxic with negative growth in all studied concentrations, with 60% mortality in the worst case. The concentration of 50 μg mL was toxic in all sizes with negative growth in the period. Therefore, the investigation of AgNPs' toxicity needs to consider a different factor to better understand their effects on aquatic plants and the environment.
由于银纳米粒子（AgNPs）具有抗菌特性，其在商业产品中的应用有所增加，因此必须研究其对环境的影响。这一情况促使我们进行了这项研究，该研究将影响 AgNPs 毒性的不同因素与水生植物浮萍（Lemna minor）联系起来，这些因素包括 AgNPs 的尺寸、积累、浓度和溶解。为此，我们将 30nm、85nm 和 110nm 三种不同尺寸的合成 AgNPs 添加到培养基中，观察其 30 天的毒性。SEM 图谱显示，由于最小的 AgNPs 具有较强的迁移性和内化作用，因此可以从根部转移到叶片中。根据奥斯特瓦尔德方程预测，30nm AgNPs 的溶解度在 30 天内增加了近 3 倍，而对于 85nm 和 110nm 尺寸的纳米粒子，7 天后，由于“奥斯特瓦尔德熟化”过程，溶解度下降。我们评估了植物死亡率，一个月后，30nm 尺寸的 AgNPs 毒性最大，所有研究浓度下均出现负生长，最坏情况下死亡率为 60%。所有尺寸的 AgNPs 在浓度为 50μg/mL 时均具有毒性，在该时间段内出现负生长。因此，研究 AgNPs 的毒性需要考虑不同的因素，以便更好地了解其对水生植物和环境的影响。
