Phytosynthesis of magnetite (Fe3O4) nanoparticles using Nepeta bornmuelleri hairy roots

Magnetic iron oxide nanoparticles (Fe3O4-NPs) offer numerous applications in agriculture, pharmaceutical, and food industries. In this study, Fe3O4-NPs were effectively phytosynthesized by environmentally friendly hairy root extracts. The A4 strain of Agrobacterium rhizogenesis was used to induce the hairy roots of Nepeta bornmuelleri. Leaves in N. bornmuelleri contain important ingredients such as 1, 8 cineol that is one of the most well-known secondary metabolites. The phytosynthesis of Fe3O4-NPs was verified and described by Ultraviolet-Visible spectroscopy, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), dynamic light scattering (DLS), and thermogravimetric analysis (TGA). The NPs were clustered with a size of less than 20 nm in FESEM analysis and 20-100 nm in TEM and HRTEM analysis. XRD pattern showed a peak of Fe3O4-NPs at 35.28° (220 nm). In the FTIR experiment, amines, alkanes, carbonyls, fluorides, and alcohols were detected as organic molecules involved in the synthesis of NPs. The average size of NPs in their liquid medium was about 53.39 nm, according to DLS analysis. According to TGA analysis, NPs maintained 82% of their weight at a temperature above 700 °C. According to the results of TGA study, Nepeta’s fast-growing hairy roots generated highly pure NPs. TGA analysis revealed that the weight loss of synthesized NPs in hairy roots was smaller than those identical samples produced in the extracts obtained from aerial parts of the plants. The 1, 8 cineol in the hairy root extracts measured by gas chromatography was found to be around 0.001%.