Improving charge collection in Escherichia coli-carbon electrode devices with conjugated oligoelectrolytes

Phys Chem Chem Phys. 2013 Apr 28;15(16):5867-72. doi: 10.1039/c3cp50437a. Epub 2013 Mar 13.

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Bioelectric Energy Sources
  • Carbon / chemistry*
  • Cell Membrane / chemistry
  • Cell Membrane / metabolism
  • Electricity
  • Electrodes
  • Electrolytes / chemistry*
  • Escherichia coli / metabolism*
  • Microscopy, Electron, Scanning
  • Quaternary Ammonium Compounds / chemical synthesis
  • Quaternary Ammonium Compounds / chemistry*
  • Stilbenes / chemical synthesis
  • Stilbenes / chemistry*

Substances

  • 4,4'-bis(4'-(N,N-bis(6''-(N,N,N-trimethylammonium)hexyl)amino)-styryl)stilbene tetraiodide
  • Electrolytes
  • Quaternary Ammonium Compounds
  • Stilbenes
  • Carbon