the growth of the bacteria. A similar approach was done by Anbuvannan and
coworkers (2015) for the fabrication of ZnO nanoparticles using A. carnosus leaf
extract. The resultant product showed improved disinfection ability for human
pathogens such as S. paratyphi, V. cholerae, S. aureus, and E. coli. Park et al.
(2017) fabricated ZnO thin films by atomic layer deposition route with the aim of
increasing reaction surface area for microbial disinfection. For this, S. aureus was
chosen as the model bacteria and a disinfection process was envisaged by the
crushed morphology caused by destruction of cell wall. The reactive oxygen species
generation and the cell wall destruction was the mechanism proposed and the effect
of Zn
2+ release was ruled out in this case. The schematic of the antibacterial activity
of the ZnO thin films proposed by Park and coworkers is given in Fig. 2.8f.
Fig. 2.8 (a) Proposed schematic of antimicrobial mechanism of flower-like ZnO (b) FESEM
images of as-synthesized flower-like ZnO. (Quek et al. 2018) (c) SEM photographs of ZnO
powders, (d) Plot of the survival number of Escherichia coli and Staphylococcus aureus with
different catalysts under UV illumination (top) and at dark condition (bottom). (Talebian et al.
2013), (e) Schematic illustration showing possible growth mechanism of ZnO-NLs. Initially, after
addition of base (NaOH) to the zinc precursor mixture, ZnO nanoparticles (nanorods) formation
occurs which may get welded to each other in a bunch to minimize their surface energy and partially
synthesized ZnO-NLs formation occurs till 90 min of the reaction which may again get welded to
each other by the remaining Zn
+2 ions in the solution to form mature leaf-shape ZnO nanoparticle at
120 min. The growth mechanism of ZnO-NLs shows, disperser assisted sonochemical method
allows time and temperature dependent controlled shape and size evolution of the nanoparticles.
(Gupta and Srivastava 2018). (f) Schematic of the antibacterial mechanisms of the ALD ZnO via
photo-produced reactive oxygen species. (Park et al. 2017)
44
R. P. Antony et al.
coworkers (2015) for the fabrication of ZnO nanoparticles using A. carnosus leaf
extract. The resultant product showed improved disinfection ability for human
pathogens such as S. paratyphi, V. cholerae, S. aureus, and E. coli. Park et al.
(2017) fabricated ZnO thin films by atomic layer deposition route with the aim of
increasing reaction surface area for microbial disinfection. For this, S. aureus was
chosen as the model bacteria and a disinfection process was envisaged by the
crushed morphology caused by destruction of cell wall. The reactive oxygen species
generation and the cell wall destruction was the mechanism proposed and the effect
of Zn
2+ release was ruled out in this case. The schematic of the antibacterial activity
of the ZnO thin films proposed by Park and coworkers is given in Fig. 2.8f.
Fig. 2.8 (a) Proposed schematic of antimicrobial mechanism of flower-like ZnO (b) FESEM
images of as-synthesized flower-like ZnO. (Quek et al. 2018) (c) SEM photographs of ZnO
powders, (d) Plot of the survival number of Escherichia coli and Staphylococcus aureus with
different catalysts under UV illumination (top) and at dark condition (bottom). (Talebian et al.
2013), (e) Schematic illustration showing possible growth mechanism of ZnO-NLs. Initially, after
addition of base (NaOH) to the zinc precursor mixture, ZnO nanoparticles (nanorods) formation
occurs which may get welded to each other in a bunch to minimize their surface energy and partially
synthesized ZnO-NLs formation occurs till 90 min of the reaction which may again get welded to
each other by the remaining Zn
+2 ions in the solution to form mature leaf-shape ZnO nanoparticle at
120 min. The growth mechanism of ZnO-NLs shows, disperser assisted sonochemical method
allows time and temperature dependent controlled shape and size evolution of the nanoparticles.
(Gupta and Srivastava 2018). (f) Schematic of the antibacterial mechanisms of the ALD ZnO via
photo-produced reactive oxygen species. (Park et al. 2017)
44
R. P. Antony et al.