Synthesis, Structural Insights, and Biomedical Evaluation of NiCoFe2O4 Nanoparticles for Antioxidant and Cancer Therapeutic Applications

Purpose: The study aims to synthesize nickel–cobalt ferrite (NiCoFe 2 O 4 ) nanoparticles with controlled Co/Ni precursor ratios and to evaluate how structural, surface, and electronic modifications influence their antioxidant and anticancer performance. Materials and Methods: NiCoFe 2 O 4 nanoparticles were synthesized via a co-precipitation route using varying Ni 2 ⁺/Co 2 ⁺ concentrations (0.025–0.1 M). Structural, morphological, and surface analyses were carried out using X-Ray Diffraction, fourier transform infrared spectroscopy, Raman, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-Ray spectroscopy, Brunauer–Emmett–Teller, and X-Ray photoelectron spectroscopy techniques. Biological functionality was assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay for antioxidant activity and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay on MCF-7 breast cancer and L929 fibroblast cells for cytotoxicity evaluation. Results: All samples exhibited a single-phase cubic spinel structure with tunable crystallite size, lattice strain, and mesoporosity. Increasing Co/Ni concentration enhanced cation redistribution, mixed valence states, and pore-volume characteristics, improving redox-active surface behavior. Among all compositions, NC4 showed the highest DPPH radical scavenging efficiency and the strongest anticancer activity, reducing MCF-7 viability to ~ 20%–30% at 100 μg/mL while maintaining >80% viability in normal L929 cells. Conclusion: Tailoring the Co/Ni precursor ratio effectively modulates the structural and surface characteristics of NiCoFe 2 O 4 nanoparticles, leading to enhanced antioxidant capacity and selective anticancer activity. These findings establish NiCoFe 2 O 4 as a promising candidate for biomedical applications, particularly in oxidative stress management and targeted cancer therapeutics.