本期Nature Communications上发表的一篇论文介绍了一个可降解的纳米颗粒系统，它能从土壤和水中吸收污染物，然后在暴露于紫外线时会聚集成块。这个平台通过将纳米颗粒的高吸收动态与清除块状材料的便利性相结合，为环境污染物的清除提供了一个新方法。

    接触废弃化学品，会增加患包括癌症和糖尿病在内的很多疾病的风险。能结合或降解污染物的纳米颗粒为水域和土壤的大量污染提供了一个解决方案。然而，人们对潜在有毒的次生产品的形成和纳米材料在环境中的持久存在有顾虑。鉴于这项技术可能带来的未知风险，重要的是要找到在治理之后将纳米材料从环境中清除的有效办法。

    Robert Langer及同事现在开发出了能从被污染的水和土壤中结合和提取化学物质的纳米颗粒。一旦用紫外线处理过，这些纳米颗粒就会将它们的外层脱掉，聚集成富含污染物的块状，后者能够很容易地被分离和清除。这样就可以使用高活性材料进行污染物提取，而不会产生在使用后纳米材料持久留在环境中的风险。用废水、热打印纸和被污染的土壤所做初步实验表明，这种处理方法可以很成功，不产生任何有毒副产物。

    原文链接：Nanoparticles with photoinduced precipitation for the extraction of pollutants from water and soil

    原文摘要：Nanotechnology may offer fast and effective solutions for environmental clean-up. Herein, amphiphilic diblock copolymers are used to develop a platform of photosensitive core-shell nanoparticles. Irradiation with ultraviolet light removes the protective layer responsible for colloidal stability; as a result, the nanoparticles are rapidly and irreversibly converted to macroscopic aggregates. The associated phase separation allows measuring the partitioning of small molecules between the aqueous phase and nanoparticles; data suggests that interactions are enhanced by decreasing the particle size. Adsorption onto nanoparticles can be exploited to efficiently remove hydrophobic pollutants from water and contaminated soil. Preliminary in vivo experiments suggest that treatment with photocleavable nanoparticles can significantly reduce the teratogenicity of bisphenol A, triclosan and 17α-ethinyl estradiol without generating obviously toxic byproducts. Small-scale pilot experiments on wastewater, thermal printing paper and contaminated soil demonstrate the applicability of the approach.