Silver nanoparticles or free silver ions work? An enantioselective phytotoxicity study with a chiral tool
Silver nanoparticles or free silver ions work? An enantioselective phytotoxicity study with a chiral tool
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银纳米颗粒或游离银离子有效吗？
DOI：
10.1016/j.scitotenv.2017.08.037
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发表时间：
2018
影响因子：
9.8
通讯作者：
Wen Yuezhong
中科院分区：
文献类型：
--
作者：
Chen Zunwei;Sheng Xiaolin;Wang Jia;Wen Yuezhong
目前，银纳米颗粒(AgNP)已经得到了广泛的应用，其对生物的潜在不利影响也引起了人们的关注。关于AgNP的确切毒性机制，目前仍有不同的看法，究竟是释放出的银离子(Ag+)还是AgNP本身造成了这种毒性还存在争议。在本研究中，我们设计了两种Ag+和AgNP共存但定量不同的暴露体系，利用半胱氨酸对映体的光还原方法，测定了它们对淡水微藻Scenedesmusoblus和模式植物拟南芥的毒性。UV-Vis和圆二色谱证实了Ag-L半胱氨酸(Ag-L-Cys)和Ag-d-半胱氨酸(Ag-d-Cys)之间的定量差异，其中Ag-L-半胱氨酸中的AgNP较多，而Ag+较少。此外，毒性测定数据显示，Ag-d-Cys对TOS的毒性更强。斜丁酸A。海南对银-L-半胱氨酸更敏感。金属元素在拟南芥叶片中的分布也受到对映选择性的影响，这与氧化胁迫有关。考虑到Ag-L-半胱氨酸和Ag-d-半胱氨酸的定量差异，可以得出结论：AgNP对S具有毒性。可受Ag+的作用而倾斜，但毒性引起TOA。Thaliana被归因于AgNP本身，而不是Ag+。本研究结果有助于更好地阐明Ag+在AgNP毒性中的作用，为研究AgNP的毒性机制提供了一种手性工具和新的视角。
Nowadays, silver nanoparticles (AgNP) have been widely used and there are raising concerns about their potential adverse effects on organism. As for the exact toxicity mechanism of AgNP, opinions still vary and whether the released silver ions (Ag+) or AgNP themselves are responsible for the toxicity remains debatable. In the present study, we have designed two exposure systems where Ag+and AgNP coexisted but differed in quantification by using photo-reduced method with cysteine enantiomers, and their toxicities to freshwater microalgaeScenedesmusobliquusand model plantArabidopsis thalianawere determined. In the results, Ag+was in suit photo-reduced by cysteine enantiomers, and the UV–Vis and circular dichroism spectrum evidence confirmed the quantification difference between Ag-l-cysteine (Ag-l-Cys) and Ag-d-cysteine (Ag-d-Cys), where there was more AgNP and less Ag+in Ag-l-Cys. Furthermore, the toxicity assay data revealed that Ag-d-Cys was more toxic toS. obliquusbutA. thalianawas more susceptible to Ag-l-Cys. The metal element distribution inArabidopsisleaves was also influenced in an enantioselective manner, which was related to the oxidative stress. Considering the quantification difference between Ag-l-Cys and Ag-d-Cys, it can be concluded that AgNP exhibited their toxicity toS. obliquusby the action of Ag+, but toxicity brought toA. thalianawas attributed to AgNP themselves rather than Ag+. The results of the present study help to better clarify the role of Ag+in AgNP toxicity and offer a chiral tool and a new sight to investigate the toxicity mechanism of AgNP.