Geobacter sulfurreducens (Gs) attachment and biofilm formation on self-assembled monolayers (SAMs) of carboxyl-terminated alkanethiol linkers with varied chain length on gold (Au) was investigated by electrochemical and microscopic methods to elucidate the effect of the surface modification on the current production efficiency of Gs cells and biofilms. At the initial stage of the cell attachment, the electrochemical activity of Gs cells at a submonolayer coverage on the SAM-Au surface was independent of the linker length. Subsequently, multiple potential cyclings indicated that longer linkers provided more biocompatible conditions for Gs cells than shorter ones. For Gs biofilms, on the other hand, the turnover current decreased exponentially with the linker length. During the biofilm formation, bacteria need to adjust from the initial planktonic state to an electrode-respiring state, which was triggered by a strong electrochemical stress found for shorter linkers, resulting in the formation of mature biofilms. Our results suggest that the initial cell attachment and the biofilm formation are two inherently different processes. Therefore, the effects of linker molecules, electron transfer efficiency and biocompatibility, must be explored simultaneously to understand both processes to increase the current production of electrogenic microorganisms in microbial fuel cells.

通过电化学和微观方法研究了在金（Au）上具有可变链长的羧基末端链烷硫醇连接基的自组装单分子膜（SAMs）上的土壤还原菌（Gs）附着和生物膜形成，以阐明表面修饰对电流的影响Gs细胞和生物膜的生产效率。在细胞附着的初始阶段，Gs细胞在SAM-Au表面亚单层覆盖下的电化学活性与接头长度无关。随后，多次潜在的循环表明，较长的接头比较短的接头为Gs细胞提供了更多的生物相容性条件。对于Gs另一方面，生物膜的周转电流随着接头长度的增加而呈指数下降。在生物膜形成过程中，细菌需要从初始的浮游状态调整为电极呼吸状态，这是由较短连接子的强电化学应力触发的，从而形成了成熟的生物膜。我们的结果表明，初始细胞附着和生物膜形成是两个固有的不同过程。因此，必须同时探索接头分子，电子转移效率和生物相容性的影响，以了解增加微生物燃料电池中当前产生电源性微生物的两个过程。