Figure 3

The antibacterial effects of different NPs on E. coli and the MIC of PAH. In the antibacterial test of NPs, bacterial cell cultures were set up at an initial optical density (OD) of 0.003 from an overnight culture. NPs solution was added into cell culture medium to reach predesigned concentrations. E. coli was exposed to 0.1, 1, 5, 10 μg/ml citrate and PAH Au NPs (A and B), and to 1, 10 μg/ml Ag NPs (C). 20 μg/ml hygromycin (Hyg) was used as a positive control and E. coli was used as a negative control. Experiment was repeated three times and the results are shown in mean ± SD. (D) The MIC of PAH against E. coli. Significant differences were observed on for the 2000 μg/ml PAH experimental group and the control group. *p<0.05.