Fig. 10. Flow cytometric analysis of (a) P. aeruginosa, (b) E. coli and (c) S. aureus. The cell viability level as indicated by fluorescein diacetate (FDA) staining (a) and (b) cytograms I: control (untreated sample); II: treated with CEN-ZnO NPs (500 μg ml⁻¹), III: (1500 μg ml⁻¹) and IV: (2500 μg ml⁻¹). (c) Cytograms I: control (untreated sample); II: S. aureus treated with CEN-ZnO NPs (16 μg ml⁻¹), III: (32 μg ml⁻¹) and IV: (64 μg ml⁻¹). Flow cytometric analysis of (d) P. aeruginosa, (e) E. coli and (f) S. aureus. Membrane internalization staining using prodidium iodide (PI). (a) and (b) Cytograms I: control (untreated sample); II: treated with CEN-ZnO NPs (500 μg ml⁻¹), III: (1500 μg ml⁻¹) and IV: (2500 μg ml⁻¹). (c) Cytograms I: control (untreated sample); II: S. aureus treated with CEN-ZnO NPs (16 μg ml⁻¹), III: (32 μg ml⁻¹) and IV: (64 μg ml⁻¹).