516309.fig.002
Figure 2: Voltage versus time discharge curve. A small, unstirred bulk electrochemical cell consisting of ferritin containing a Fe(OH)2 mineral core connected to a ferritin containing Co(OH)3 mineral core in 0.05 M MOPS pH 8.0 was discharged at a drain rate of 100 nA. Each ferritin contained ~2000 metal ions per mineral core.