Fig. 3.

Bacterial viability. For a, b E. coli (OD₆₀₀ ~ 0.05) and B. subtilis (OD₆₀₀ ~ 0.05) that are treated with POAA and chitosan and incubated with a POAA and b chitosan to achieve the concentration of 0–100 μg mL⁻¹ with nutrient medium for 3 h at 37 °C. The incubated bacteria were then diluted to a dilution factor of 10⁻⁵–10⁻⁸ and plated on the agar plates. The plates were incubated aerobically at 37 °C for 12–16 h. After incubation, the number of surviving bacteria was measured using by colony forming unit (CFU) counting assay was determined and switched the unit to percentage (%) which corresponds to the unit of CFU mL⁻¹ (***p < 0.0001, **p < 0.001 and *p < 0.01 obtained by Student’s t-test), c–f Growth curves for bacteria. GO, GO-POAA, and GO-chitosan (GO materials, up to 20 μm wide, were delivered in a dose of 50 μg mL⁻¹) were added to (c,e) E. coli (OD₆₀₀ ~ 0.05), and d, f B. subtilis (OD₆₀₀ ~ 0.05) and then incubated with either c, d nutrient or e, f PBS alone at 37 °C for 3 h. The absorbance at an optical density of 600 nm was recorded. Data are mean ± SD (n = 6)