Clemson University Institute of Environmental Toxicology, Pendleton, South Carolina, USA.
Environ Toxicol Chem. 2013 Oct;32(10):2356-64. doi: 10.1002/etc.2300. Epub 2013 Aug 9.
The most persistent question regarding the toxicity of silver nanoparticles (AgNPs) is whether this toxicity is due to the nanoparticles themselves or the silver ions (Ag(+)) they release. The present study investigates the role of surface coating and the presence of dissolved organic carbon on the toxicity of AgNPs to Daphnia magna and tests the hypothesis that the acute toxicity of AgNPs is a function of dissolved Ag produced by nanoparticle dissolution. Toxicity of silver nitrate (AgNO3) and AgNPs with surface coatings-gum arabic (AgGA), polyethylene glycol (AgPEG), and polyvinylpyrrolidone (AgPVP)-at 48 h was assessed in US Environmental Protection Agency moderately hard reconstituted water alone and augmented with Suwannee River dissolved organic carbon (DOC). As expected, AgNO3 was the most toxic to D. magna and AgPVPs were the least toxic. In general, Suwannee River DOC presence reduced the toxicity of AgNO3, AgGAs, and AgPEG, while the toxicity of AgPVPs was unaffected. The measured dissolved Ag concentrations for all AgNPs and AgNO3 at the 48-h median lethal concentration in moderately hard reconstituted water were similar. The presence of Suwannee River DOC decreased the ratio of measured dissolved Ag to measured total Ag concentration. These results support the hypothesis that toxicity of AgNPs to D. magna is a function of dissolved Ag concentration from these particles.
关于纳米银颗粒（AgNPs）毒性最持久的问题是，这种毒性是源于纳米颗粒本身还是它们释放的银离子（Ag(+)）。本研究调查了表面涂层的作用和溶解有机碳的存在对大型溞（Daphnia magna）中 AgNPs 毒性的影响，并验证了这样一个假设，即 AgNPs 的急性毒性是纳米颗粒溶解产生的溶解银的函数。在单独使用美国环保署中硬度再构成水和添加苏湾河溶解有机碳（DOC）的情况下，评估了硝酸银（AgNO3）和具有表面涂层-阿拉伯树胶（AgGA）、聚乙二醇（AgPEG）和聚乙烯吡咯烷酮（AgPVP）的 AgNPs 在 48 小时时对大型溞的毒性。正如预期的那样，AgNO3 对大型溞的毒性最大，而 AgPVP 则毒性最小。一般来说，苏湾河 DOC 的存在降低了 AgNO3、AgGA 和 AgPEG 的毒性，而 AgPVP 的毒性则不受影响。在中硬度再构成水中，所有 AgNPs 和 AgNO3 的 48 小时半数致死浓度下测量的溶解银浓度相似。苏湾河 DOC 的存在降低了测量的溶解银与测量的总银浓度的比值。这些结果支持了这样一个假设，即 AgNPs 对大型溞的毒性是这些颗粒中溶解银浓度的函数。
