Surface-enhanced Raman scattering from intracellular and extracellular bacterial locations
Surface-enhanced Raman scattering from intracellular and extracellular bacterial locations
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DOI：
10.1021/ac800838v
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发表时间：
2008-09-01
影响因子：
7.4
通讯作者：
Goodacre, Royston
中科院分区：
文献类型：
--
作者：
Jarvis, Roger M.;Law, Nicholas;Goodacre, Royston
虽然表面增强拉曼散射（Sers）可以将拉曼截面增加4-6个数量级，但是为了使Sers有效，分析物必须化学键合或紧密接近所使用的金属表面。因此，大多数研究微生物的生化成分的研究都引入了金或银纳米颗粒的外部供应。因此，迄今为止，Sers对细菌的研究几乎完全集中在革兰氏阴性外细胞膜的细胞外分析上。细菌细胞通常尺寸小至0.5 x 1 μ m，并且很难将纳米尺寸的胶体金属颗粒引入到这个微小的环境中。然而，异化金属还原细菌，包括希瓦氏菌和吉伯氏菌，可以减少范围广泛的高价金属离子，通常在细胞内，和Ag（I）和Au（III），这可能会导致形成胶体零价颗粒。在这里，我们报告，为第一次，Sers的细菌Geetriumsulfreducens促进胶体金颗粒沉淀在细胞内。此外，我们显示Sers从相同的生物体离子银，这导致在胶体银沉积在细胞表面上的减少。
While surface-enhanced Raman scattering (SERS) can increase the Raman cross-section by 4-6 orders of magnitude, for SERS to be effective it is necessary for the analyte to be either chemically bonded or within close proximity to the metal surface used. Therefore most studies investigating the biochemical constituents of microorganisms have introduced an external supply of gold or silver nanoparticles. As a consequence, the study of bacteria by SERS has to date been focused almost exclusively on the extracellular analysis of the Gram-negative outer cell membrane. Bacterial cells typically measure as little as 0.5 by 1 mu m, and it is difficult to introduce a nanometer sized colloidal metal particle into this tiny environment. However, dissimilatory metal-reducing bacteria, including Shewanella and Geobacter species, can reduce a wide range of high valence metal ions, often within the cell, and for Ag(I) and Au(III) this can result in the formation of colloidal zero-valent particles. Here we report, for the first time, SERS of the bacterium Geobacter sulfurreducens facilitated by colloidal gold particles precipitated within the cell. In addition, we show SERS from the same organism following reduction of ionic silver, which results in colloidal silver depositions on the cell surface.