Conference Proceeding

Antimicrobial properties of ZnO nanostructures: nanoparticles and self-cleaning nanorod-covered surfaces

Dr. Zivile Luksiene,
Vilnius university, Lithuania

Dr. Zivile Luksiene, is a Professor, Supreme researcher, head of the division of modern technologies in biomedical sciences, Institute of Applied Research, Vilnius university. She obtained her Ph.D. from Department of Biophysics Moscow University, in 1985. Her field of specializing in Antimicrobial photo nanotechnologies for the safety of food and water, for the preservation of crops and post harvest, for prevention of infectious diseases. Dr. Zivile Luksiene current research focused on "Innovative approaches to inactivate harmful and pathogenic microorganisms in agriculture". Dr. Zivile Luksiene is a professional member of the international organization like European Society for Photobiology (Netherlands), European Federation of Food Science and Technology (EFFosT): special interest group on food safety, World harmonization initiative, etc. Dr. Zivile Luksiene has published more than 119 publications, 145 presentations in the international conferences.

In recent years, a rapid development of nanotechnology opens up whole universe of new possibilities for biomedicine, industry and agriculture. It is well documented that most of the harmful and pathogenic microorganisms are able to develop high resistance to many conventional chemical disinfectants. Moreover, currently chemical sanitizers are suspected to be environmentally unsound, as they are associated with occupational and operational hazards, are potentially harmful for humans. Thus, during the past decade the emphasis in microbial decontamination has shifted from using chemicals to various alternative techniques including physical antimicrobials. To this end, the development of novel nano-sized zinc oxide (ZnO) nanoparticles and nanorod-covered surfaces seems promising. It is important to note that ZnO is not only stable and has longer life than organic-based disinfectants, but also is generally regarded as safe to human beings. So, these properties open new prospects of their application in agriculture and biomedicine. The aim of this work was to evaluate the antimicrobial efficiency of ZnO nanoparticles (NPs) in suspension and ZnO nanorod-covered surface after photoactivation with visible light against several pathogenic bacteria (E. coli O157:H7, Salmonella enterica, Listeria monocytogenes, Enterococcus faecalis) and harmful fungi (Botrytis cinerea). Obtained results indicate that in the presence of visible light (400 nm) ZnO NPs (1×10-3 M) reduced population of all bacteria by 7 log (CFU/ml). Clear dependence of antimicrobial properties of ZnO NPs on used concentration and incubation time was found. Scanning electron microscopy images of treated bacteria indicate that treatment induced cell wall disintegration and lysis. Results obtained on examination of antifungal activity of ZnO NPs reveal that significant photoinactivation (58%) of B. cinerea was observed at NPs concentration 5×10-3 M. SEM analysis confirmed that substantial morphological changes occur in the microfungus after treatment. The data suggest that ZnO nanorod-covered surface in the presence of visible light exhibit strong antibacterial activity against all pathogenic bacteria (E. coli O157:H7, Salmonella enterica, Listeria monocytogenes, Enterococcus faecalis) and their biofilms. In conclusion, ZnO NPs in the presence of visible light exhibit strong antibacterial and antifungal activity. Such ZnO NPs properties obviously could be used for the development of effective fungicides in agriculture or innovative physical antibacterial agents, so important in medicine and food microbial control. Moreover strong antimicrobial properties of ZnO nanorod-covered surfaces could be used for the development of effective liquid disinfection systems (waste water) and self-cleaning antimicrobial surfaces.

Published: 27 April 2017