Bioynthesis and characterization of zinc oxide nanoparticles (ZnO-NPs) using Passiflora foetida Linn leaves extract and their biological applications

Nanotechnology is a rapidly expanding branch of scientific research. The use of plants to synthesize nanoparticles has gained interest as an environmentally friendly. The green synthesis of zinc oxide nanoparticles (ZnO-NPs) mediated leaf extract is gaining importance due to its cost-effectiveness and eco-friendly nature. Herein, ZnO-NPs were synthesized, utilizing Passiflora foetida (P. foetida) aqueous leaf extract as a reducing and stabilizing agent. The synthesized ZnO-NPs were employed to characterize using UV–Vis, XRD, IR, and FE-SEM with EDAX, HR-TEM, and zeta potential. According to the data, the UV–vis spectra exhibited an absorption peak at 430 nm. The FT-IR spectra of the synthesized ZnO-NPs exposed the presence of eight functional groups. The X-ray diffraction pattern revealed the crystalline structure of the ZnO nanoparticles. The FE-SEM and HR-TEM of the synthesized ZnO-NPs evaluated spherical form with size ranging from 50 to 90 nm, and the EDaX spectrum demonstrated the presence of strong Zn signals. Furthermore, the synthesized ZnO-NPs have significant antibacterial activity, with the highest zone of inhibition observed in E. coli (18.75 mm) at 50 µg. The antioxidant study of the synthesized ZnO-NPs displayed remarkable activity against DPPH and H2O2 radical scavenging assays with an IC50 value of 111.92 and 95.29 µg/mL respectively. The synthesized ZnO-NPs have shown significant anticancer activity against the A549 cell line, with an IC50 value of 44.56 μg/mL. In addition, the synthesized ZnO-NPs showed strong efficacy against Cx. quinquefasciatus larvae (LC50 and LC90 values of 1.756 and 9.975 mg/mL, respectively). Thus, the synthesized ZnO-NPs revealed substantial biological activities and could be considered an alternative source of medicine as well as the production of novel drugs in the future.