Electrochemical wiring of the Gram-positive bacterium Enterococcus faecalis with osmium redox polymer modified electrodes

The Gram-positive bacterium Enterococcus faecalis was investigated to test its ability to electrochemically communicate with electrodes. E. faecalis cells were successfully “wired” to gold electrodes through [Os(2,2′-bipyridine)₂-poly(N-vinylimidazole)₁₀Cl]^2 +/+ redox polymer. Maximum current density achieved in response to 10 mM D-glucose was 18 ± 1 μA cm^− 2. Control experiments without redox polymer showed no current response. This demonstrates the efficiency of the osmium-based mediator in electron transfer between the cells having a thick cell wall and the electrode. The findings have significant importance in microbial electrochemistry for further understanding of microbe-electrode interactions.