Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003, USA.
Nat Nanotechnol. 2011 Aug 7;6(9):573-9. doi: 10.1038/nnano.2011.119.
Electronic nanostructures made from natural amino acids are attractive because of their relatively low cost, facile processing and absence of toxicity. However, most materials derived from natural amino acids are electronically insulating. Here, we report metallic-like conductivity in films of the bacterium Geobacter sulfurreducens and also in pilin nanofilaments (known as microbial nanowires) extracted from these bacteria. These materials have electronic conductivities of ∼5 mS cm(-1), which are comparable to those of synthetic metallic nanostructures. They can also conduct over distances on the centimetre scale, which is thousands of times the size of a bacterium. Moreover, the conductivity of the biofilm can be tuned by regulating gene expression, and also by varying the gate voltage in a transistor configuration. The conductivity of the nanofilaments has a temperature dependence similar to that of a disordered metal, and the conductivity could be increased by processing.
由天然氨基酸制成的电子纳米结构因其成本相对较低、易于加工和无毒而具有吸引力。然而，大多数源自天然氨基酸的材料都是电绝缘的。在这里，我们报告了细菌脱硫弧菌薄膜以及从这些细菌中提取的菌毛纳米丝（称为微生物纳米线）的金属样导电性。这些材料的电子电导率约为 5 mS cm(-1)，与合成金属纳米结构相当。它们还可以在厘米级的距离上进行传导，这是细菌大小的数千倍。此外，通过调节基因表达，以及在晶体管结构中改变栅极电压，生物膜的电导率可以进行调节。纳米丝的电导率具有类似于无序金属的温度依赖性，并且通过加工可以提高电导率。
