Abstract:
Environmental pollutants are one of the most series global issues today. Dyes are recognized as
one of the roots for environmental pollution. Methyl orange (MO) are a type of dyes which can be
found in various branches of textile, leather, and paper printing industries. In recent years,
microbial infections are considered as a serious issue in human health worldwide. The
advancement of nanotechnology based on bio-synthesis of medicinal plant supported nanoparticles
has improved therapeutic capacity of ZnO nanoparticles. The main objective of this study was to
synthesize ZnO nanoparticles using Lepidium sativum seed extract for their photocatalytic and
antibacterial activities. The plant mediated synthesized ZnO nanoparticles was prepared from
macerated extract of Lepidium sativum seeds, zinc acetate dihydrate and sodium hydroxides at
room temperature. The synthesized ZnO nanoparticles were characterized by UV-Vis, FT-IR
spectroscopic techniques and Powder XRD analysis. The color change observed in the nanoparti
cle’s solution and the sharp peak at 376 nm in the UV–Vis region suggested that the formation of
small-sized ZnO nanoparticles. The color changed during the preliminary phytochemical
investigation and the FT-IR spectroscopic analysis suggested the presence of flavonoids, tannin,
saponin and Alkaloids which could be responsible for the stabilization of the synthesized ZnO
nanoparticles. The XRD studies the synthesized zinc oxide nanoparticles has crystalline size of 29
nm which predict as hexagonal structure. The photocatalytic activity of MO dye degradation was
efficient in the presence ZnO nanoparticle catalyst as compared to in the absence of ZnO
nanoparticle catalyst. Finally, the bio-assay test showed 13 to 24 zone of inhibition for zinc oxide
nanoparticles and 11 to 16 zone of inhibition for plant extract against different bacterial strains.
The highest activity was observed against Klebsiella for zinc oxide nanoparticles compared to
plant extract alone, which might be due to synergistic effect.
