Figure 4.

Silver ions perturb bacterial respiratory chain, inducing intracellular ROS generation.

Notes: (A) Total Ag uptake in E. coli (left panel) and its distribution (right panel); (B) alteration of NAD⁺/NADH ratio in E. coli with different treatments as indicated, *P<0.05 versus the negative control; and (C) the intracellular ROS generation. The concentrations of Cit@AgNPs, AgNO₃, GSH, and Na₂S₂O₃ were 15 μg/mL, 0.5 μg/mL, 1.0 mM, and 0.1 mM, respectively, *P<0.05 versus the negative control. The exposure lasted for 6 h.

Abbreviations: AgNPs, silver nanoparticles; GSH, glutathione; ROS, reactive oxygen species; E. coli, Escherichia coli; Cit, citrate; MPA, mercaptopropionic acid; MHA, mercaptohexanoic acid; MPS, mercaptopropionic sulfonic acid.