Figure 3: Dose-dependent effects of Ag nanowires (NWs), Ag nanospheres, and AgNO3 on two recombinant Escherichia coli strains after 4h exposure. (a) Inhibition of the light output in bioluminescent E. coli; (c) induction of the bioluminescence of the Ag+-induced E. coli. Filled columns in (b) indicate EC50 values calculated from panel (a) (see horizontal dotted line); filled columns in (d) indicate induction threshold values calculated from panel (c) (see horizontal dotted line). Open columns in (b) and (d) with numerical values show mg of dissolved Ag/L at EC50 or induction threshold, respectively. Mean ± standard deviation of two independent experiments is shown: a—significant ( ) difference from AgNO3, b—significant ( ) difference from AgNO3 and Ag NW.