Disinfection as a term has been known since ancient times and has served humans as a prevention and control of infectious diseases. Methods of treating water with chlorine and chlorine compounds have been hampered by new findings that talk about chlorine damage to humans and the environment, newer methods such as ozone are expensive and require technology development, the use of ionizing radiation also leaves negative environmental impacts. Due to above-mentioned limitations, it is necessary develop new „green“ methodologies having a great potential, both in disinfecting and economic terms. Such methods involve also ultraviolet irradiation, a non-ionizing radiation that has an antibacterial effect, does not leave residues, does not harm the environment and does not require great worker protection and expensive technological adaptation. Such a method shows some limitations as well, and it is up to the current generation to go beyond these constraints with new products and technologies with improved performances, thus continuing the good hygiene practices that humanity has perfected throughout history. In this thesis, the antibacterial properties of zinc oxide on a polymer support in combination with UV - A radiation were investigated. The activation of zinc oxide by photoabsorbtion of ultraviolet radiation activates zinc oxide, thus producing reactive oxidative hydroxy radicals and peroxide, which expose the bacterial cell to oxidative stress and inactivate it, while the UV radiation itself damages the genetic content of the bacterium and its repair mechanisms. The study was performed at the Faculty of Medicine, University of Rijeka in cooperation with the University of Rijeka, Department of Physics, and was financially supported by the Croatian Science Foundation under project “Preparation of Porous Thin-film Materials for Water Purification using Atomic Layer Deposition (ALD) “(IP-2016-06-3568). Our studies showed that zinc oxide on a polymer carrier in combination with UV irradiation exhibits photoinactivation antibacterial properties after 15 - 30 minutes of illumination,showing a great potential of this material to be used as an effective substrate in water disinfection.