Fig. 6

Bacterial viability shown by fluorescence and quantification. Images and viabilities of a bare E. coli and B. subtilis after treatment with GO, GO-POAA, and GO-chitosan and 3 h of incubation with b either nutrient c or PBS. The bacteria were stained using a LIVE/DEAD kit to obtain the fluorescent images, and d quantified for viability was estimated (GO materials, up to 20 μm wide, were delivered in a dose of 50 μg mL⁻¹). Negative control (0 μg mL⁻¹): bare bacteria without any treatment. For the live % for both bacteria treated with PBS, p = 0.832 and p = 0.419 are the group of bacteria with no materials treatment and bacteria with GO treatment in PBS; p = 0.325 and p = 0.097 are the group of bacteria with no materials treatment and bacteria with GO-POAA treatment in PBS; p < 0.001 and p < 0.001 are the group of bacteria with no materials treatment and bacteria with GO-chitosan treatment in PBS. Data are mean ± SD (n = 6). *p value obtained by Student’s t-test