A biomicrosystem for simultaneous optical and electrochemical monitoring of electroactive microbial biofilm

This work reports a novel microsystem for the sensing and characterization of electrochemically active bacterial biofilm. A three-electrode configuration integrated in the microsystem provided the unprecedented use of electrochemical analysis including electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) for monitoring bacterial electron transfers. Transparency of the device simultaneously visualized different stages of bacterial biofilm development. This technique allowed for both optical and electrical studies of the microbial biofilm and provides valuable information between the cell growth/biofilm development and the extracellular electron transfer processes associated with microbial energy production. In particular, this microsystem demonstrated the potential synergistic cooperation between cyanobacteria and two archetype exoelectrogenic bacterial species, which can be exploited in developing self-sustainable microbial bioelectricity production.