Green synthesis of zinc oxide nanoparticles and its antibacterial Activity on Pseudomonas aeruginosa

Abstract

Zinc oxide (ZnO) nanoparticles have wide-ranging applications and can be synthesized using environmentally friendly green synthesis methods as an alternative to conventional approaches. Pseudomonas aeruginosa (P. aeruginosa) is an extremely perilous bacterium known for its multidrug-resistant (MDR) nature, posing a significant threat to hospitalized patients and those with compromised immune systems. The bacterium's ability to withstand multiple antibiotics, combined with its capacity to form biofilms, contributes to its high rates of morbidity and mortality. The intrinsic resistance of P. aeruginosa, along with its ability to form biofilms, further complicates treatment and exacerbates the severity of infections, particularly in susceptible patient populations. Objective: The main objective of this study was to utilize extracts from Ocimum basilicum leaves in a green synthesis approach to produce zinc oxide nanoparticles. Additionally, the research aimed to assess the antibacterial effectiveness of these synthesized nanoparticles against P. aeruginosa. Materials and Methods: In this study, ZnO nanoparticles were synthesized using the leaf extract of O. basilicum plants under various parameters. The biosynthesis of zinc oxide nanoparticles was verified using a UV-visible spectrophotometer and characterized using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), and Fourier Transform Infrared Spectroscopy (FTIR). The synthesized ZnO nanoparticles exhibited significant antibacterial efficacy. Specifically, they demonstrated antimicrobial activity against P. aeruginosa pathogens. Different concentrations of both O. basilicum extract and synthesized ZnO nanoparticles were tested against P. aeruginosa and observed antibacterial activity. Results: indicated that the ZnO NPs synthesized from O. basilicum exhibited stronger antibacterial activity compared to the plant extract alone. The most effective concentrations were found to be 1.0, 1.5, and 3 mg/ml of prepared ZnO nanoparticles. Increasing the concentration of ZnO nanoparticles resulted in enhanced inhibition of bacterial growth in P. aeruginosa. Conclusion: The green synthesis of ZnO NPs using plant extracts has demonstrated significant antibacterial activity against P.aeruginosa. The high concentration of the ZnO NPs resulted in larger inhibition zones at higher concentrations. These findings underscore the possibility of green-synthesized ZnO NPs as an antimicrobial agent for P. aeruginosa. The environmentally friendly and cost-effective nature of the green synthesis method further enhances its appeal for future applications in antibacterial treatments.