Biogenic Fe₃O₄ Nanoparticles Synthesized from Rubus ellipticus: Phytochemical Profiling, Structural Characterization,...

The present study reports the green synthesis of iron oxide nanoparticles (Fe₃O₄ NPs) using the ethanolic leaf extract of Rubus ellipticus (RE), supported by GC-MS profiling. 48 phytochemicals including stigmast-5-en-3-ol, phytol, linoleic acid ethyl ester, neophytadiene, and vitamin E acted as natural reducing and stabilizing agents. The RE-mediated Fe₃O₄ nanoparticles (RE-Fe) were characterized by using XRD, TEM-EDX, and the XPS analysis. XRD confirmed the highly crystalline, phase-pure magnetite with a cubic spinel structure, and TEM revealed about the quasi-spherical particles averaging 37.73 ± 6.03 nm. XPS validated the mixed Fe²⁺/Fe³⁺ oxidation states typical of the Fe₃O₄. The Biological evaluation showed the excellent antioxidant activity of the RE-Fe compared to the extract, with an IC₅₀ values of 27.93 and 39.06 µg/mL in DPPH and the phosphomolybdate assays. Antidiabetic assays demonstrated the strong α-amylase and the α-glucosidase inhibition (IC₅₀ = 49.54 and 35.21 µg/mL), outperforming the plant extract. RE-Fe also exhibited the potent antibacterial activity against the bacterial strains E. coli and S. aureus, comparable to ciprofloxacin. Molecular docking supported these outcomes, revealing strong interactions of key phytochemicals with TyrRS, DNA gyrase, α-amylase, and α-glucosidase. Overall, Rubus ellipticus is shown to be an effective source for eco-friendly Fe₃O₄ NPs synthesis with promising biomedical applications.