Bioelectronics

Modification of Microbes with Transmembrane Wires and Applications in Bioelectrochemical Devices

The spontaneous insertion of biocompatible, semiconducting molecular wires (for example, see 1 and Figure 1A) across microbial membranes leads to the facilitation of cell–electrode interactions.  This has important consequences for bio-based energy production and bioelectrosynthetic systems.

We have demonstrated increased electricity generation in microbial fuel cells (Figure 1B) using electrode-attached molecular-wire-modified microorganisms in comparison to their unmodified counterparts.  Coupled with a reduction in the amount of organic substrate present in the fuel cell medium, we envision application of this cell modification strategy to wastewater treatment with concomitant production of useable electrical energy.

Figure 1 –(A) Confocal microscopy image of molecular-wire-stained E. coli. (B) Schematic representation of a microbial fuel cell employing molecular-wire-modified microbes for wastewater treatment and electrical power generation.

Conversely, by facilitating use of an electrode as an electron donor, we have also demonstrated an influence in microbial metabolite production using molecular-wire-modified microorganisms.  This is potentially a unique route to carbon fixation and to obtaining value-added products from biological systems.

We are working to deepen our mechanistic understanding of the role of molecular wire intercalation in stimulating cell–electrode interactions.  Such insight is expected to guide future design of molecular wires with increased microbial specificity and increased charge extraction and injection efficiency.