Construction and oxygen reduction performance of polydopamine functionalized Escherichia coli bioelectrocatalyst

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摘要：

细胞外电子传递(Extracellular Electron Transport,EET)能力是影响微生物电催化剂催化活性的关键因素,然而,缓慢的生物-非生物界面EET效率严重限制了微生物燃料电池(Microbial Fuel Cell,MFC)中阴极氧还原反应(Oxygen Reduction Reaction,ORR)的生物电催化性能.通过在单个大肠杆菌(E.coli)细胞表面原位包覆共轭导电聚多巴胺(PDA)功能性涂层,有效提高了微生物细胞的界面导电性和黏附性,并且不影响其生物活性.与天然的大肠杆菌相比,经过PDA修饰的大肠杆菌作为ORR的生物电催化剂时,EET效率显著提高,实现了更大的ORR电催化活性,氧还原电流密度达到2.62 mA·cm-2.此外,采用PDA修饰的大肠杆菌作为生物阴极组成的MFC的最大输出功率密度达到95.3μW·cm-2,与天然的大肠杆菌相比提高了1.14倍.研究结果表明,共轭导电聚合物PDA具有氨基、酚基等亲水基团,可以提高底物的亲水性,还具有醌基可以加速细胞外呼吸过程中的电子转移,利用其修饰细菌可以赋予细菌更多的额外功能,例如导电性和黏附性,进而有效提高其电催化性能,为制备高活性生物电催化材料以及提高MFC的产电性能提供了一种有前途的策略.

The extracellular electron transport(EET)ability is a key factor affecting the catalytic activity of microbial electrocatalysts.However,the slow bio-abiotic interface EET efficiency severely limits the bioelectrocatalytic performance of cathodic oxygen reduction(ORR)in microbial fuel cells(MFCs).In this paper,by in-situ coating conjugated conductive polydopamine(PDA)functional coating on the surface of single Escherichia coli(E.coil) cells,the interfacial conductivity and adhesion of microbial cells were effectively improved without affecting their biological activity.Compared with the native E.coil,the PDA-modified E.coil was used as the bioelectrocatalytic catalyst for ORR,the EET efficiency was significantly improved,and the electrocatalytic activity of ORR was greater.The oxygen reduction current density reached 2.62 mA·cm~(-2).In addition,the maximum output power density of the MFC composed of E.coil modified with PDA as the bio-cathode is 95.3 μW·cm~(-2),which is 1.14 times higher than that of the native E.coil.The results show that the conjugate conductive polymer PDA has amino,phenolic and other hydrophilic groups,which can improve the hydrophilicity of the substrate,and also quinone group can accelerate the electron transfer in the process of extracellular respiration,using its modification of bacteria can give bacteria more additional functions,such as conductivity and adhesion,and then effectively improve their electrocatalytic performance.It provides a promising strategy for preparing bioelectrocatalytic materials with high activity and improving the electrical performance of MFC.

作者：

白正宇邢宝凤牛洋娣

Bai Zhengyu;Xing Baofeng;Niu Yangdi(School of Chemistry and Chemical Engineering,Henan Normal University,Xinxiang 453007,China)

机构地区：

betway官方app 化学化工学院

出处：

《betway官方app 学报:自然科学版》 CAS 北大核心 2023年第5期30-36,F0002,共8页

Journal of Henan Normal University(Natural Science Edition)

基金：

国家自然科学基金(51922008,52271176)。

关键词：

生物电催化剂细胞外电子传递氧还原反应功能性涂层微生物燃料电池