Electric wiring of bacteria using redox polymers and selective measurement of metabolic activity in the presence of surrounding planktonic bacteria.

Non-electroactive bacteria (n-EAB), constituting the majority of known bacteria to date, have been underutilized in electrochemical conversion technologies due to their lack of direct electron transfer to electrodes. In this study, we established an electric wiring between n-EAB (gram-positive Bacillus subtilis and gram-negative Escherichia coli) and an extracellular electrode via a ferrocene-polyethyleneimine-based redox polymer (Fc-PEI). Chronoamperometry recordings indicated that Fc-PEI can transfer intracellular electrons to the extracellular electrode regardless of the molecular organization of PEI (linear or branched) and the membrane structure of bacteria (gram-positive or -negative).

Minimally invasive current-controlled electrical stimulation system for bacteria using highly capacitive conducting polymer-modified electrodes.

This paper proposes a minimally invasive current-controlled electric stimulation system based on a poly(3,4-ethylenedioxythiophene) (PEDOT)-modified electrode to characterize the dynamics of the membrane potential in Bacillus subtilis. A highly capacitive PEDOT-modified electrode enabled the injection of a large ionic charge to the surface of the cells suppressing cytotoxic pH change in the vicinity of the electrode. The current pulse induced a hyperpolarization response in B.