فهرست نشریات علمی دسترسی آزاد ایران

Manganese dioxide (MnO₂) nanoparticles were synthesized using two different methods: an environmentally friendly green synthesis using flaxseed extract as a natural reducing and stabilizing agent, and a conventional chemical precipitation method employing sodium thiosulfate (Na₂S₂O₃·5H₂O). Spectroscopic and structural characterization techniques (UV-Vis DRS, XRD, TEM, FESEM, EDX, and FTIR) revealed that the synthesis method significantly influenced the optical and structural properties of the nanoparticles. MnO₂ nanoparticles obtained via green synthesis exhibited the β-MnO₂ phase and had a band gap energy of 1.57 eV, whereas those produced by the chemical method exhibited the α-MnO₂ phase with a higher band gap of 2.06 eV. To assess their biological activity, cytotoxicity was evaluated against pancreatic cancer cells using the MTT assay. The results showed that both nanoparticle types caused a significant reduction in cell viability at high concentrations (500 µg/mL), while no significant cytotoxic effects were observed at lower concentrations (≤ 31.25 µg/mL). The IC₅₀ values indicated that the biosynthesized nanoparticles had greater cytotoxic potential (39.6 µg/mL) compared to the chemically synthesized ones (73.5 µg/mL), highlighting the influence of synthesis method on biological performance.