Fig. 4
From: Nanoscale membranes that chemically isolate and electronically wire up the abiotic/biotic interface
Chemical, protonic, and electron transport across membrane. a Cyclic voltammograms of pure SiO2 on Pt/SnO2 electrode (no wires, red trace) and SiO2-encapsulated PV3 on Pt/SnO2 electrode (correct wires, green trace). Inset: Redox wave of FeII(CN)6/ FeIII(CN)6 with Pt/SnO2 electrode (bare anode). Scale bar 2.5 mA cm−2. These scans were performed at a rate of 0.1 V s−1 in the presence of 1 mM of K4FeII(CN)6 and K3FeIII(CN)6 aqueous solution. The cathodic peak at −0.4 V arises from the reaction of H+ with Pt to form H-Pt. b Chronoamperometry at +0.6 V vs. of S. oneidensis on SiO2-encapsulated PV3 on Pt/SnO2 electrode (correct wires, black trace); pure SiO2 on Pt/SnO2 electrode (no wires, blue trace); SiO2-encapsulated PV3_SO3− on Pt/SnO2 electrode (wrong wires, red trace) and S. oneidensis ΔmtrB mutant with SiO2-encapsulated PV3 on Pt/SnO2 electrode (green trace). Onset of current coincides with addition of S. oneidensis to the electrochemical cell after a period of current stabilization. Second rise of current indicates addition of lactate. Inset: S. oneidensis on Pt/SnO2 (bare anode). c Confocal fluorescence microscopic images measured after 24 h chronoamperometric measurement presented in b of Pt/SnO2 electrode (1); PV3-SiO2 on Pt/SnO2 electrode (2); and pure SiO2 on Pt/SnO2 electrode (3). Scale bar is 10 µm for all images
