Silver Release from Silver Nanoparticles in Natural Waters
Silver Release from Silver Nanoparticles in Natural Waters
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DOI：
10.1021/es304023p
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发表时间：
2013-05-07
影响因子：
11.4
通讯作者：
Bernier-Latmani, R.
中科院分区：
文献类型：
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作者：
Dobias, J.;Bernier-Latmani, R.
银纳米颗粒（AgNP）由于其抗微生物性质而越来越多地用于消费品中。这种增加的使用引起了生态问题，因为AgNP释放到环境中。一旦释放，零价银可被氧化成Ag+，释放阳离子，或者其可作为AgNP持续存在。银的化学形式有其毒性的影响，因此，它是至关重要的表征银纳米粒子的持久性，以预测其生态毒理学潜力。在这项研究中，我们评估了从暴露于河流和湖泊水长达4个月的各种大小的银纳米粒子的银的释放。还考虑了几种AgNP封端剂：聚乙烯吡咯烷酮（PVP）、单宁酸（Tan）和柠檬酸（Cit）。我们观察到5，10和50纳米银纳米粒子之间的显着差异，后者更耐溶解在有氧水中的质量基础上。然而，当Ag被表面积归一化时，差异减小，这表明表面积在确定Ag损失中的重要作用。我们建议，快速的初始Ag+释放是由于从纳米颗粒表面的Ag+解吸。我们还观察到PVP-和Tan-AgNP比Cit-AgNP更容易释放Ag+。此外，也可能发生氧化溶解，但速率较慢。这项研究清楚地表明，小的AgNP（5 nm，PVP和Tan）溶解迅速，几乎完全溶解，而较大的AgNP（50 nm）有可能持续很长一段时间，可以作为Ag离子的连续来源。
Silver nanoparticles (AgNPs) are used increasingly in consumer products for their antimicrobial properties. This increased use raises ecological concern because of the release of AgNPs into the environment. Once released, zero-valent silver may be oxidized to Ag+ and the cation liberated or it may persist as AgNPs. The chemical form of Ag has implications for its toxicity; it is therefore crucial to characterize the persistence of AgNPs to predict their ecotoxicological potential. In this study, we evaluated the release of Ag from AgNPs of various sizes exposed to river and lake water for up to 4 months. Several AgNP-capping agents were also considered: polyvinylpyrrolidone (PVP), tannic acid (Tan), and citric acid (Cit). We observed a striking difference between 5, 10, and 50 nm AgNPs, with the latter being more resistant to dissolution in oxic water on a mass basis. However, the difference decreased when Ag was surface-area-normalized, suggesting an important role of the surface area in determining Ag loss. We propose that rapid initial Ag+ release was attributable to desorption of Ag+ from nanoparticle surfaces. We also observed that PVP- and Tan-AgNPs are more prone to Ag+ release than Cit-AgNPs. In addition, it is likely that oxidative dissolution also occurs but at a slower rate. This study clearly shows that small AgNPs (5 nm, PVP and Tan) dissolve rapidly and almost completely, while larger AgNPs (50 nm) have the potential to persist for an extended period of time and could serve as a continuous source of Ag ions.