Fig. 4

TEM images. Bacteria with or without GO, GO-POAA, and GO-chitosan are characterized by TEM: a bare E. coli and B. subtilis without any treatment. The formation of an external barrier of GO sheets and GO-based materials on the surfaces of these two bacteria after 30 min of incubation with b either nutrient c or PBS, respectively. (GO materials, up to 20 μm wide, were delivered in a dose of 50 μg mL⁻¹)