title: Improving charge collection in Escherichia coli-carbon electrode devices with conjugated oligoelectrolytes.
abstract: It is important to tailor biotic-abiotic interfaces in order to maximize the utility of bioelectronic devices such as microbial fuel cells (MFCs), electrochemical sensors and bioelectrosynthetic systems. The efficiency of electron-equivalent extraction (or injection) across such biotic-abiotic interfaces is dependent on the choice of the microbe and the conductive electrode material. In this contribution, we show that spontaneous intercalation of a conjugated oligoelectrolyte, namely 4,4'-bis(4'-(N,N-bis(6''-(N,N,N-trimethylammonium)hexyl)amino)-styryl)stilbene tetraiodide (DSSN+), into the membranes of Escherichia coli leads to an increase in current generation in MFCs containing carbon-based electrodes. A combination of scanning electron microscopy (SEM) and confocal microscopy was employed to confirm the incorporation of DSSN+ into the cell membrane and biofilm formation atop carbon felt electrodes. Current collection was enhanced by more than 300% with addition of this conjugated oligoelectrolyte. The effect of DSSN+ concentration on electrical output was also investigated. Higher concentrations, up to 25 μM, lead to an overall increase in the number of charge equivalents transferred to the charge-collecting electrode, providing evidence in support of the central role of the synthetic system in improving device performance.
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore.
authors.forename: Victor Bochuan
authors.initials: VB
authors.lastname: Wang
authors.forename: Jenny
authors.initials: J
authors.lastname: Du
authors.forename: Xiaofen
authors.initials: X
authors.lastname: Chen
authors.forename: Alexander W
authors.initials: AW
authors.lastname: Thomas
authors.forename: Nathan D
authors.initials: ND
authors.lastname: Kirchhofer
authors.forename: Logan E
authors.initials: LE
authors.lastname: Garner
authors.forename: Myat Thiri
authors.initials: MT
authors.lastname: Maw
authors.forename: Wee Han
authors.initials: WH
authors.lastname: Poh
authors.forename: Jamie
authors.initials: J
authors.lastname: Hinks
authors.forename: Stefan
authors.initials: S
authors.lastname: Wuertz
authors.forename: Staffan
authors.initials: S
authors.lastname: Kjelleberg
authors.forename: Qichun
authors.initials: Q
authors.lastname: Zhang
authors.forename: Joachim Say Chye
authors.initials: JS
authors.lastname: Loo
authors.forename: Guillermo C
authors.initials: GC
authors.lastname: Bazan
mesh_terms: D001674:Bioelectric Energy Sources; D002244:Carbon / Q000737:chemistry*; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D004560:Electricity; D004566:Electrodes; D004573:Electrolytes / Q000737:chemistry*; D004926:Escherichia coli / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D000644:Quaternary Ammonium Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D013267:Stilbenes / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: C583448:4,4'-bis(4'-(N,N-bis(6''-(N,N,N-trimethylammonium)hexyl)amino)-styryl)stilbene tetraiodide; D004573:Electrolytes; D000644:Quaternary Ammonium Compounds; D013267:Stilbenes; D002244:Carbon