| 微米级核壳量子点团聚体在生物膜中的扩散与溶解及其毒性 |
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| 引用本文： | 赵佳玥,张道勇,潘响亮.微米级核壳量子点团聚体在生物膜中的扩散与溶解及其毒性[J].环境科学研究,2017,30(8):1303-1309. |
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| 作者姓名： | 赵佳玥 张道勇 潘响亮 |
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| 作者单位： | 1.中国科学院新疆生态与地理研究所, 新疆干旱区环境污染与生态修复重点实验室, 新疆 乌鲁木齐 830011 |
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| 基金项目： | 中国科学院“百人计划”项目 |
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| 摘 要： | 包括量子点在内的人工纳米颗粒是近年来突出的环境污染物，为确定其在生物膜中的扩散过程和特征，应用TIRF（全内反射荧光）、FRAP（荧光漂白后恢复）等技术，研究了CdTe/CdS/ZnS核壳式量子的微米级的团聚体在细菌Comamonas testoteroni生物膜表面的吸附动力学、生物膜内部的扩散及其在生物膜中的溶解和毒性.结果表明:通过TIRF技术观察到生物膜可快速吸附>1 μm的CdTe/CdS/ZnS核壳式量子点团聚体，而且通过CLSM（激光扫描共聚焦荧光显微镜）进行深度扫描发现，量子点团聚体吸附到生物膜表面后可以进一步扩散到生物膜深层，在25 min内可穿透45 μm的生物膜，并在生物膜中随深度呈线性分布特征.FRAP分析表明，量子点团聚体被生物膜固定后还具有较强的移动性，漂白区的荧光强度在5 min可恢复30%.量子点团聚体在生物膜中会溶解产生Cd2+、Zn2+等重金属离子，从而对生物膜产生毒性并杀死细菌.研究显示，虽然纳米颗粒进入环境中会形成微米级的团聚体，但依然可以进入生物膜，对水生微生物生态系统产生危害.TIRF、CLSM和FRAP技术是研究纳米颗粒物在生物膜表面吸附和内部扩散动力学的有效工具.
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| 关 键 词： | 纳米颗粒 量子点 生物膜 全内反射荧光(TIRF) 荧光漂白后恢复(FRAP) |
| 收稿时间： | 2016/12/29 0:00:00 |
| 修稿时间： | 2017/5/1 0:00:00 |
Diffusion and Toxicity of Micrometer CdTe/CdS/ZnS Core-Shell-Shell Quantum Dot Aggregates in Biofilm |
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| ZHAO Jiayue,ZHANG Daoyong and PAN Xiangliang.Diffusion and Toxicity of Micrometer CdTe/CdS/ZnS Core-Shell-Shell Quantum Dot Aggregates in Biofilm[J].Research of Environmental Sciences,2017,30(8):1303-1309. |
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| Authors: | ZHAO Jiayue ZHANG Daoyong and PAN Xiangliang |
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| Affiliation: | 1.Xinjiang Key Laboratory of Environmental Pollution and Bioremediation, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China2.College of Environment, Zhejiang University of Technology, Hangzhou 310014, China3.University of Chinese Academy of Sciences, Beijing 100049, China |
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| Abstract: | Nanoparticles including quantum dots are emerging pollutants. Adsorption and subsequent diffusion of nanoparticles in biofilm are still not well known. Adsorption kinetics, diffusion, dissolution and toxicity of the micrometer-size aggregates of the model nanoparticles, CdTe/CdS/ZnS core-shell-shell quantum dot (QD), in Comamonas testoteroni biofilm were investigated using Total Internal Reflection Fluorescence (TIRF) and Fluorescence Recovery After Photobleaching (FRAP). It was demonstrated that C. testoteroni could adsorb aggregates of CdTe/CdS/ZnS QDs (>1 μm), and could further diffuse into deeper layers of the biofilm and penetrate the 45 μm thick biofilm within 25 mins. The amount of accumulated QDs in microlayers of the biofilm decreased linearly with depth. The FRAP results showed that about 30% fluorescence intensity recovered within 5 min, indicating the mobility of QDs in the biofilm. The QDs dissolved in the biofilm and thus released heavy metals and exerted toxic effects on the biofilm. The results revealed that nanoparticles can penetrate into the biofilm and posed a great risk to aquatic ecosystems, although they may aggregate in the aquatic environment. TIRF, CLSM and FRAP are convenient and powerful tools for characterizing adsorption and diffusion of nanoparticles in biofilm. |
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| Keywords: | nanoparticles quantum dots biofilm total internal reflection fluorescence (TIRF) fluorescence recovery after photobleaching (FRAP) |
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