Figure 8: Scanning electron microscopy (SEM) of PTA NPs-treated and untreated cells. SEM micrographs of E. coli and S. aureus: untreated E. coli (A) and S. aureus (B); E. coli (C and E) and S. aureus (D and F) 3 and 2 h respectively, after exposure to PTA NPs (50 μg mL-1). Arrows indicate the presence of PTA NPs.