Fig. 2.

Gently treated Synechocystis cells generate an enhanced photocurrent using an endogenous redox mediator. a Schematic drawing of the bio photo-electrochemical apparatus with the iSyn settled on the working electrode (WE). The counter electrode (CE) is platinum, and the reference electrode (RE) an Ag/AgCl/3 M NaCl. All electrodes are connected to the potentiostat (P). b Chronoamperometric measurements at 150 mV (vs. Ag/AgCl/3 M NaCl) for iSyn in the presence (blue) or absence of DCMU (red). The yellow up arrow indicates light on (the initial 100 seconds show the dark current) and the black down arrow indicates light off. c Cyclic voltammograms of iSyn, illuminated (solid blue lines) or in the dark (dashed blue lines). Buffer lacking iSyn shows no redox activity (black solid line). Measurements recorded at a rate of 5 mV s⁻¹