Optimization of hematite nanoparticles from natural ore as novel imaging agents: A Green Chemistry approach

In this research, we propose an environmentally friendly method for producing hematite nanoparticles (H-NPs) from natural hematite ore, focusing on their application as efficient contrast agents in x-ray and computed tomography (CT) imaging for medical purposes. The process involves the reduction of iron oxide within the ore to attain the desired hematite phase, crucial for synthesizing H-NPs. To ensure sustainability, we adopted a Green Chemistry approach, utilizing a combination of carbon soot and limestone for the purification process, thereby achieving eco-conscious production. The produced H-NPs were thoroughly characterized using various analytical techniques, such as x-ray fluorescence (XRF), x-ray diffraction (XRD), Fourier transmission infrared spectroscopy (FT-IR), and FESEM-EDX (field emission scanning electron microscopy-energy-dispersive x-ray spectroscopy). XRD analysis confirmed the crystalline rhombohedral hexagonal lattice structure, while FT-IR spectra indicated the presence of characteristic Fe–O stretching modes in line with the expected molecular composition. FESEM-EDX imaging unveiled agglomerated particles, ranging in size from 54.6 to 149.9 nm for iron ore and 22 nm for H-NPs. These particles were primarily composed of iron (Fe) and oxygen (O). The magnetic properties of the H-NPs were investigated through vibrating sample magnetometer (VSM) studies, highlighting their distinct ferromagnetic behavior. Of particular significance, the H-NPs demonstrated exceptional performance as contrast agents in both x-ray and CT imaging. Even at minimal concentrations, they exhibited remarkable x-ray absorption capabilities. CT scans further validated their exceptional absorptive capacity. These findings emphasize the potential of H-NPs as valuable assets in medical imaging, serving as sustainable tools for enhanced diagnostic applications. The study showcases an eco-conscious approach to harnessing natural resources, paving the way for a greener and more effective utilization of H-NPs in the medical imaging landscape.