Insecticidal and antibacterial properties of zinc oxide nanoparticles (ZnO-NPs) synthesized from Phoebe zhennan leaf extract

Abstract

Chemical insecticides are used to control most insect pests, which are harmful to the environment and humans. In this study, green synthesis of zinc oxide nanoparticles (ZnO-NPs) was carried out by using extracts from the Phoebe zhennan plant leaf. X-ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM), ultraviolet–visible spectroscopy, and Fourier transform infrared spectroscopy (FTIR) confirmed the successful synthesis and structural characteristics of nanoparticles. The forest insect pest Plagiodera versicolora Laicharting is used to evaluate the bioactivity of nanoparticles. Mortality in P. versicolora was found to be dose- and time-dependent after different treatments of nanoparticles. The study determined the lethal concentration values (LC₅₀ and LC₉₀) of nanoparticles against P. versicolora, revealing a time-dependent efficacy with the LC₅₀ of 22.47 mg/L and LC₉₀ of 81.2 mg/L at 96 h. The findings revealed the lethal time values (LT₅₀ and LT₉₀) of the nanoparticles against P. versicolora, with maximum efficacy observed at a concentration of 50 mg/L, resulting in an LT₅₀ of 27.24 h and an LT₉₀ of 62.71 h. In addition, the antibacterial activity of nanoparticles was also evaluated against Bacillus subtilis, and the results showed significant inhibition of bacterial growth in a dose-dependent manner. The study demonstrated the potential of nanoparticles as an insect control and antimicrobial agent. This research provides valuable insights into the green synthesis of nanoparticles and emphasizes the need for further exploration of their safety and efficacy in various practical applications.