Potential influence of graphene doped Ni_0.75Zn_0.25Fe₂O₄ nano spinel ferrites on structure, magnetic, antimicrobial, anti-inflammatory, and anticancer assessments

Ni_0.75Zn_0.25Fe₂O₄/x% graphene (x = 0–20%) nanoparticles were synthesized via sol–gel method and characterized structurally and morphologically. X-ray diffraction confirmed the cubic spinel structure (Fd-3m) with crystallite sizes of 33–79 nm. Whlie, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed grain sizes of 44–60 nm and particle sizes ~50 nm (at 2% graphene), with using high resolution-TEM showed an interplanar spacing of 0.35 nm. Selected area electron diffraction (SAED) patterns indicated good crystallinity with polycrystalline features. Also, fourier transform infrared spectroscopy (FT-IR) analysis estimated Fe–O bond stiffness as 2.1 and 1.07 dyne/cm at tetrahedral and octahedral sites, respectively. Notably, vibrating sample magnetometer (VSM) measurements showed soft ferrimagnetic behavior with variable magnetization (37.85–56.26 emu/g) and coercivity (140.22–154.27 G) depending on graphene content. Antimicrobial tests revealed significant activity against Gram-negative bacteria (notably E. coli), but not against fungi or Gram-positive strains. Nanoparticles showed strong anti-inflammatory activity (LC₅₀ = 45.14 µg/mL), compared to Celecoxib and notable cytotoxicity against MCF-7 cancer cells, with reduced cell viability to as low as 6.82% at higher doses. These findings highlight the potential of prepared nanocomposites for biomedical applications, particularly in drug delivery and cancer therapy for achieving good health and well-being as one of pivots of sustainable development.