Stability, Bioavailability, and Bacterial Toxicity of ZnO and Iron-Doped ZnO Nanoparticles in Aquatic Media

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• 作者：Minghua Li ; Suman Pokhrel ; Xue Jin ; Lutz M盲dler ; Robert Damoiseaux ; Eric M. V. Hoek
• 刊名：Environmental Science & Technology
• 出版年：2011
• 出版时间：January 15, 2011
• 年：2011
• 卷：45
• 期：2
• 页码：755-761
• 全文大小：316K
• 年卷期：v.45,no.2(January 15, 2011)
• ISSN：1520-5851

文摘

The stability and bioavailability of nanoparticles is governed by the interfacial properties that nanoparticles acquire when immersed in a particular aquatic media as well as the type of organism or cell under consideration. Herein, high-throughput screening (HTS) was used to elucidate ZnO nanoparticle stability, bioavailability, and antibacterial mechanisms as a function of iron doping level (in the ZnO nanoparticles), aquatic chemistry, and bacterial cell type. 味-Potential and aggregation state of dispersed ZnO nanoparticles was strongly influenced by iron doping in addition to electrolyte composition and dissolved organic matter; however, bacterial inactivation by ZnO nanoparticles was most significantly influenced by Zn²⁺ ions dissolution, cell type, and organic matter. Nanoparticle IC₅₀ values determined for Bacillus subtilis and Escherichia coli were on the order of 0.3鈭?.5 and 15鈭?3 mg/L (as Zn²⁺), while the IC₅₀ for Zn²⁺ tolerant Pseudomonas putida was always >500 mg/L. Tannic acid decreased toxicity of ZnO nanoparticles more than humic, fulvic, and alginic acid, because it complexed the most free Zn²⁺ ions, thereby reducing their bioavailability. These results underscore the complexities and challenges regulators face in assessing potential environmental impacts of nanotechnology; however, the high-throughput and combinatorial methods employed promise to rapidly expand the knowledge base needed to develop an appropriate risk assessment framework.