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首页> 外文期刊>Environmental Science & Technology >Cysteine-lnduced Modifications of Zero-valent Silver Nanomaterials: Implications for Particle Surface Chemistry, Aggregation, Dissolution, and Silver Speciation
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Cysteine-lnduced Modifications of Zero-valent Silver Nanomaterials: Implications for Particle Surface Chemistry, Aggregation, Dissolution, and Silver Speciation

机译：半胱氨酸诱导的零价银纳米材料的修饰：粒子表面化学，聚集，溶解和银形态的含义。

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摘要

The persistence of silver nanopartides in aquatic environments and their subsequent impact on organisms depends on key transformation processes, which include aggregation, dissolution, and surface modifications by metal-complexing ligands. Here, we studied how cysteine, an amino acid representative of thiol ligands that bind monovalent silver, can alter the surface chemistry, aggregation, and dissolution of zero-valent silver nanopartides. We compared nanopartides synthesized with two coatings, citrate and polyvinylpirrolidone (PVP), and prepared nanoparticle suspensions (approximately 8 μM total Ag) containing an excess of cysteine (400 μM). Within 48 h, up to 47% of the silver had dissolved, as indicated by nitration of the samples with a 0.025-μm filter. Initial dissolution rates were calculated from the increase of dissolved silver concentration when particles were exposed to cysteine and normalized to the available surface area of nanopartides in solution. In general, the rates of dissolution were almost 3 times faster for citrate-coated nanopartides relative to PVP-coated nanopartides. Rates tended to be slower in solutions with higher ionic strength in which the nanopartides were aggregating. X-ray absorption spectroscopy analysis of the partides suggested that cysteine adsorbed to silver nanopartides surfaces through the formation of Ag(+I)-sulfhydryl bonds. Overall, the results of this study highlight the importance of modifications by sulfhydryl-containing ligands that can drastically influence the long-term reactivity of silver nanopartides in the aquatic environment and their bioavailability to exposed organisms. Our findings demonstrate the need to consider multiple interlinked transformation processes when assessing the bioavailability, environmental risks, and safety of nanopartides, particularly in the presence of metal-binding ligands.
机译：银纳米粒子在水生环境中的持久性及其对生物的影响取决于关键的转化过程，包括聚集，溶解和金属络合配体对表面的修饰。在这里，我们研究了半胱氨酸（一种代表与单价银结合的硫醇配体的氨基酸）如何改变零价银纳米粒子的表面化学，聚集和溶解。我们比较了用两种涂层柠檬酸盐和聚乙烯吡咯烷酮（PVP）合成的纳米颗粒，并制备了含有过量半胱氨酸（400μM）的纳米颗粒悬浮液（总银量约为8μM）。在48小时内，溶解了多达47％的银，如使用0.025-μm过滤器硝化样品所表明的。当颗粒暴露于半胱氨酸并归一化为溶液中纳米粒子的可用表面积时，由溶解银浓度的增加来计算初始溶解速率。通常，相对于PVP涂层的纳米粒子，柠檬酸盐涂层的纳米粒子的溶解速率几乎快3倍。在纳米粒子聚集的具有较高离子强度的溶液中，速率趋于降低。该部分的X射线吸收光谱分析表明，半胱氨酸通过形成Ag（+ I）-巯基键而吸附到纳米银表面。总的来说，这项研究的结果突出了含巯基的配体进行修饰的重要性，这种配体可以极大地影响纳米银纳米粒子在水生环境中的长期反应性及其对裸露生物的生物利用度。我们的发现表明，在评估纳米粒子的生物利用度，环境风险和安全性时，尤其是在存在金属结合配体的情况下，需要考虑多个相互关联的转化过程。

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  • 来源
    《Environmental Science & Technology》 |2012年第13期|p.7037-7045|共9页
  • 作者

    Andreas P. Gondikas; Amanda Morris; Brian C. Reinsch; Stella M. Marinakos; Gregory V. Lowry; Heileen Hsu-Kim;

  • 作者单位

    Department of Civil and Environmental Engineering, Duke University, Box 90287, Durham, North Carolina 27708, United States,Center for the Environmental Implications of NanoTechnology (CEINT), P.O. Box 90287, Durham, North Carolina 27708, United States;

    Department of Civil and Environmental Engineering, Duke University, Box 90287, Durham, North Carolina 27708, United States,Center for the Environmental Implications of NanoTechnology (CEINT), P.O. Box 90287, Durham, North Carolina 27708, United States;

    Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States,Center for the Environmental Implications of NanoTechnology (CEINT), P.O. Box 90287, Durham, North Carolina 27708, United States;

    Center for the Environmental Implications of NanoTechnology (CEINT), P.O. Box 90287, Durham, North Carolina 27708, United States;

    Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States,Center for the Environmental Implications of NanoTechnology (CEINT), P.O. Box 90287, Durham, North Carolina 27708, United States;

    Department of Civil and Environmental Engineering, Duke University, Box 90287, Durham, North Carolina 27708, United States,Center for the Environmental Implications of NanoTechnology (CEINT), P.O. Box 90287, Durham, North Carolina 27708, United States;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);美国《化学文摘》(CA);
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