微生物还原石墨烯修饰碳毡电极的电化学特征

Electrochemical characteristics of microbe reduced graphene modified carbon felt electrodes

本文探讨了腐败希瓦氏菌(ShewanellaputrefaciensATCC8071)与生物呼吸驱动下自组装3D-br-GO修饰碳毡电极之间相互作用的电化学特性,并且进一步探究了施加+0.1V(vs. Ag/Ag Cl)电势于生物电极对其相互作用的影响.X射线衍射检测表明GO在微生物呼吸驱动下生成了还原态氧化石墨烯(br-GO).扫描电镜图像显示GO修饰电极表面有大量的br-GO包裹细菌的复合结构,说明br-GO对微生物具有较好的生物相容性,且由微生物呼吸驱动得到的三维br-GO自组装地修饰到生物电极上增加了其比表面积和细菌负载量.通过生物膜生长过程中的产电监测、循环伏安法测试,结果表明GO的修饰有利于细菌附着于电极形成活性生物膜,促进了微生物与电极之间的电子转移.而施加+0.1V(vs.Ag/Ag Cl)电势于GO修饰的电极,结果显示电极上仅有少量的细菌负载,没有形成活性生物膜,微生物与电极之间的电子转移行为明显减少,表明施加+0.1V(vs.Ag/Ag Cl)电势可能对电极上微生物呼吸生长有抑制作用.

In the current study,electrochemical characteristics of interaction between Shewanella putrefaciens ATCC 8071 and self-assembled 3D bio-reduced GO(3D-br-GO)modified carbon felt electrodes driven by biological respiration were investigated,and the effect of+0.1V(vs.Ag/AgCl)potential applied to the bioelectrode on the interaction was further explored.X-ray diffraction showed that GO was reduced to br-GO driven by microbial respiration.SEM images showed a large number of br-GO/bacteria composites shaped on the GO-modified electrode surface,which indicated that the br-GO had good biocompatibility,and the self-assembled 3D-br-GO modified electrode could increase its specific surface area and bacterial loading capacity.By monitoring of electricity production during biofilm growth,and testing of cyclic voltammetry,the results showed that the modification of GO was beneficial for the bacteria to attach onto the electrode in order to form active biofilm and enhanced the electron transfer between microbe and electrode.Whereas,the applied potential of+0.1V(vs.Ag/AgCl)on the GO modified electrode resulted in only a small quantity of bacteria colonized on the electrode,and no formed active biofilm.The electron transfer behavior between the microbe and the electrode was significantly reduced,indicating that the applied potential of+0.1V(vs.Ag/AgCl)may inhibit the growth of microorganisms on the electrode surface.