Biosynthesis and Characterization of Copper Nanoparticles Using Shewanella oneidensis: Application for Click Chemistry
Biosynthesis and Characterization of Copper Nanoparticles Using Shewanella oneidensis: Application for Click Chemistry
复制标题
DOI：
10.1002/smll.201703145
复制
发表时间：
2018-03-08
期刊：
影响因子：
13.3
通讯作者：
Lloyd, Jonathan R.
中科院分区：
文献类型：
--
作者：
Kimber, Richard L.;Lewis, Edward A.;Lloyd, Jonathan R.
纳米铜作为多相催化剂具有广泛的应用前景。在本研究中，我们提出了一种新的绿色生物合成路线，利用金属还原细菌希瓦氏杆菌来生产铜纳米颗粒。薄片透射电子显微镜显示，铜纳米颗粒主要存在于细胞内，典型的尺寸范围为20-40 nm。连续的块面扫描电子显微镜显示，铜纳米颗粒均匀分散在细胞的三维结构中。X射线吸收近边光谱和扩展X射线吸收精细结构分析表明，纳米粒子为Cu(0)，但原子分辨图像和电子能量损失谱表明，暴露在空气中时，表面层部分氧化为Cu2O。纳米铜的催化活性表现在典型的“点击化学”反应中，在叠氮-炔环加成反应中产生良好的产率，很可能是由纳米颗粒的铜(I)表面层催化的。此外，细胞色素缺失突变体表明，一种新的金属还原系统参与了酶促铜(II)还原和铜-NP的合成，而不依赖于该细菌中通常用于还原其他高氧化态金属的MTR途径。这项工作展示了一种新的、简单的、绿色的生物合成方法来生产高效的纳米铜催化剂。
Copper nanoparticles (Cu-NPs) have a wide range of applications as heterogeneous catalysts. In this study, a novel green biosynthesis route for producing Cu-NPs using the metal-reducing bacterium, Shewanella oneidensis is demonstrated. Thin section transmission electron microscopy shows that the Cu-NPs are predominantly intracellular and present in a typical size range of 20-40 nm. Serial block-face scanning electron microscopy demonstrates the Cu-NPs are well-dispersed across the 3D structure of the cells. X-ray absorption near-edge spectroscopy and extended X-ray absorption fine-structure spectroscopy analysis show the nanoparticles are Cu(0), however, atomic resolution images and electron energy loss spectroscopy suggest partial oxidation of the surface layer to Cu2O upon exposure to air. The catalytic activity of the Cu-NPs is demonstrated in an archetypal "click chemistry" reaction, generating good yields during azide-alkyne cycloadditions, most likely catalyzed by the Cu(I) surface layer of the nanoparticles. Furthermore, cytochrome deletion mutants suggest a novel metal reduction system is involved in enzymatic Cu(II) reduction and Cu-NP synthesis, which is not dependent on the Mtr pathway commonly used to reduce other high oxidation state metals in this bacterium. This work demonstrates a novel, simple, green biosynthesis method for producing efficient copper nanoparticle catalysts.