Antimicrobial activity of rare earth metal doped ZnO thin films prepared by low cost spray technique against fish pathogens

Abstract

Abstract The global problem of antibiotic resistance endangers public health. Antibiotic resistance genes can be transmitted along by bacteria in humans, animals, and aquatic species and abuse of antibiotics causes the aforementioned problem. The widespread use of antibiotics in aquaculture has a number of detrimental consequences for both the industry and consumer health. ZnO-based nanoparticles may eventually replace some traditional antibiotics due to their antibacterial activity and low toxicity. The purpose of this study is to evaluate the antibacterial properties of yttrium-doped zinc oxide (ZnO:Y) nanoparticles against many important fish infections. In the current work, undoped and Yttrium (2, 4, and 6 at%) doped ZnO thin films were prepared using a simplified Spray pyrolysis technique and tested for antimicrobial efficacy against Aeromonashydrophila, Salmonella enterica, Lactococcusgarvieae, and Streptococcus agalactiae. Synthesised samples' structural, morphological, and optical properties were investigated. XRD spectrum revealed a well-organized crystallite hexagonal wurzite structure. The average transmittance of the undoped ZnO and ZnO:Y films in the 600 to 1200 nm wavelength range is 75%. In SEM, undoped ZnO thin films had evenly dispersed, spherical-shaped grains, whereas yttrium doped ZnO thin films had a tetra pod chain-like structure with an improved surface-to-volume ratio.Despite the fact that the complete Y doped film (2,4 and6 at. % of Y) was found as having robust antibacterial activity, the 4 at.% of Y doped ZnO sample displayed the highest activity against the tested pathogens. The current findings show that the zone of inhibition was greater against gram negative bacterial strains Aeromonashydrophila and Salmonella entericathan against gram positive strainsLactococcusgarvieae and Streptococcus agalactiae.