Sonochemical-driven green synthesis of Fe₃O₄ nanoparticles as MRI contrast agents

This study reports a green and scalable sonochemical synthesis of superparamagnetic iron oxide (Fe₃O₄) nanoparticles using Rhus coriaria (sumac) extract as a phytochemical reducing and stabilizing agent. The proposed method integrates environmentally responsible green chemistry with high-efficiency sonochemistry to produce Fe₃O₄ nanoparticles exhibiting excellent crystallinity, colloidal stability, and magnetic properties. Compared to conventional chemical synthesis using citric acid, the green-synthesized Fe₃O₄@sumac nanoparticles achieved significantly higher saturation magnetization (85 emu/g) and transverse relaxivity (r₂ = 259.8 mM⁻¹s⁻¹), supporting their potential as MRI contrast agents. Zeta potential analysis indicated enhanced colloidal stability (−43.1 mV), and transmission electron microscopy imaging confirmed reduced nanoparticle agglomeration compared to the chemically synthesized counterpart. Structural and elemental analyses demonstrated enhanced phase purity and reduced agglomeration, while cytotoxicity studies on HEK-293 cells indicated excellent biocompatibility, even at high concentrations. This dual-route comparative study is the first to demonstrate that phytochemical-rich sumac extract can enhance both the magnetic and biomedical performance of Fe₃O₄ nanoparticles when synthesized via an energy-efficient sonochemical approach. The findings contribute to the advancement of environmentally friendly synthesis methods for magnetic nanomaterials with potential applications in biomedical imaging.