Effect of Zr⁴⁺ dopants on micro-structural and antibacterial characteristics of CuFe₂O₄ nanoparticles produced via sol-gel auto combustion

This study explores the impact of zirconium (Zr⁴⁺) substitution on the structural, magnetic, and antibacterial properties of copper ferrite (CuFe₂O₄) nanoparticles synthesized using the sol-gel auto-combustion method. The synthesis approach ensured uniform composition and controlled stoichiometry. X-ray diffraction (XRD) confirmed the formation of a cubic spinel phase with average crystallite sizes ranging from 30 to 50 nm. Microstructural analysis using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed cube-shaped particles with sizes ranging from 13 to 17 nm and significant agglomeration due to magnetic interactions. Magnetic characterization showed a decrease in magnetization (Ms) with increasing Zr⁴⁺ concentration, attributed to the introduction of non-magnetic ions, while coercivity (Hc) remained moderate, indicating suitability for biomedical applications. Antibacterial testing demonstrated enhanced activity against both Gram-positive and Gram-negative bacteria with Zr⁴⁺ substitution, suggesting improved surface interaction and ion release mechanisms. These findings highlight the potential of Zr⁴⁺-doped CuFe₂O₄ nanoparticles as a promising candidate to address challenges in combating bacterial resistance, with implications for biomedical and environmental applications.