Magnetic Fe-doped ZnO nanocomposites: concentration-driven tuning of biocompatibility and antimicrobial potency

Abstract

This work reports the first systematic investigation of the structural, biocompatibility, and antimicrobial properties of Fe–ZnO/Fe₂O₃ nanocomposites (NCPs), highlighting the influence of Fe doping across a wide range (0.05–11 wt%) and the formation of Fe₂O₃ at higher concentrations. The nanocomposites were synthesized via a controlled chemical route and comprehensively analyzed through photocatalytic, antiglycation, and biological assays. Structural and magnetic characterization confirmed the formation of Fe₂O₃ at concentrations of ≥1 wt% Fe, which modifies the crystalline and magnetic profiles. Increasing the Fe content reduced photocatalytic efficiency due to electron–hole recombination but enhanced antiglycation activity, revealing therapeutic potential against AGE-related diseases. Biocompatibility assays (RAW 264.7 macrophages) indicated reduced ROS generation and higher cell viability, while antimicrobial assays confirmed strong inhibition of S. aureus and P. aeruginosa. In vivo Drosophila assays demonstrated improved survival and reduced intestinal cytotoxicity compared to pure ZnO. These results confirm Fe–ZnO/Fe₂O₃ NCPs as promising, low-toxicity multifunctional materials for biomedical and environmental applications.