Affiliation:
1. Department of Environmental Science and Engineering University of Science and Technology of China Hefei 230026 China
2. State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and Engineering Tongji University Shanghai 200092 China
3. Department of Chemical Physics University of Science and Technology of China Hefei 230026 China
Abstract
AbstractElectroactive microbial cells have evolved unique extracellular electron transfer to conduct the reactions via redox outer‐membrane (OM) proteins. However, the electron transfer mechanism at the interface of OM proteins and nanomaterial remains unclear. In this study, the mechanism for the electron transfer at biological/inorganic interface is investigated by integrating molecular modeling with electrochemical and spectroscopic measurements. For this purpose, a model system composed of OmcA, a typical OM protein, and the hexagonal tungsten trioxide (h‐WO3) with good biocompatibility is selected. The interfacial electron transfer is dependent mainly on the special molecular configuration of OmcA and the microenvironment of the solvent exposed active center. Also, the apparent electron transfer rate can be tuned by site‐directed mutagenesis at the axial ligand of the active center. Furthermore, the equilibrium state of the OmcA/h‐WO3 systems suggests that their attachment is attributed to the limited number of residues. The electrochemical analysis of OmcA and its variants reveals that the wild type exhibits the fastest electron transfer rate, and the transient absorption spectroscopy further shows that the axial histidine plays an important role in the interfacial electron transfer process. This study provides a useful approach to promote the site‐directed mutagenesis and nanomaterial design for bioelectrocatalytic applications.
Funder
National Natural Science Foundation of China
Youth Innovation Promotion Association
Fundamental Research Funds for the Central Universities
Subject
General Physics and Astronomy,General Engineering,Biochemistry, Genetics and Molecular Biology (miscellaneous),General Materials Science,General Chemical Engineering,Medicine (miscellaneous)