Figure 5. Evaluation of the effect of the CDs on biofilms. (a-b) The absorbance of the crystal violet stained solutions at 590 nm after treatment of S. aureus (a) and S. typhimurium (b) biofilms with different concentrations of the CD for 48 h under light irradiation and in the dark. Inset shows the corresponding photographs of the crystal violet stained solutions after treatment of S. aureus (a) and S. typhimurium (b) biofilms with different concentrations of the CD for 48 h under irradiation and in the dark. (c-d) The absorbance of the crystal violet stained solutions at 590 nm after treatment of S. aureus (c) and S. typhimurium (d) with different concentrations of the CD for 48 h under light and in the dark. Inset denotes the corresponding photographs of crystal violet stained suspensions after treatment of S. aureus (c) and S. typhimurium (d) with different concentrations of the CD for 48 h under irradiation and in the dark. Note that the concentration of the CD in each well in all the photographs corresponds to that of thex -axis towards below. (e) Schematic illustration of the disruptive and inhibitory effects of the CDs on biofilm.