In fact, PF presented a ZI of 6 mm against P. aeruginosa and of 20 mm against S. aureus while
it is just, respectively, 6 mm and 12 mm for CS.
The difference can be seen when looking at pictures in Fig. 4. in fact, antibacterial activities of dyes are dependent on chemical structure and functional groups presented in dye molecules (Zhang et al., 2014).