A Fe₂O₃–CuO–CuFe₂O₄ nanocomposite was synthesized using the sol-gel method with ethanol as a reactive fuel. X-ray diffraction confirmed the presence of Fe₂O₃, CuO, and CuFe₂O₄ phases, with an average crystallite size of 60–95 nm. UV-visible spectroscopy indicated an energy bandgap of 4 eV. Scanning electron microscopy revealed a porous and heterogeneous surface morphology. The nanocomposite showed antibacterial activity against gram-positive S. aureus, with a maximum zone of inhibition (ZOI) of 9 mm at the highest concentration, but no effect against gram-negative E. coli. The nanocomposite's optical, structural, and antibacterial properties make it suitable for applications in optoelectronics, sensors, medicine, and energy storage. The study highlights the potential of the nanocomposite for advanced functional materials due to its controlled composition and phase purity. The antibacterial activity is attributed to the generation of reactive oxygen species (ROS) and the release of heavy metal ions, which disrupt bacterial cell structures. The nanocomposite's optical properties, including a bandgap of 4 eV, suggest its potential for photocatalytic applications and electronic devices. The study also discusses the significance of the nanocomposite's structure and composition in determining its properties, emphasizing the importance of optimizing synthesis conditions to enhance its performance.A Fe₂O₃–CuO–CuFe₂O₄ nanocomposite was synthesized using the sol-gel method with ethanol as a reactive fuel. X-ray diffraction confirmed the presence of Fe₂O₃, CuO, and CuFe₂O₄ phases, with an average crystallite size of 60–95 nm. UV-visible spectroscopy indicated an energy bandgap of 4 eV. Scanning electron microscopy revealed a porous and heterogeneous surface morphology. The nanocomposite showed antibacterial activity against gram-positive S. aureus, with a maximum zone of inhibition (ZOI) of 9 mm at the highest concentration, but no effect against gram-negative E. coli. The nanocomposite's optical, structural, and antibacterial properties make it suitable for applications in optoelectronics, sensors, medicine, and energy storage. The study highlights the potential of the nanocomposite for advanced functional materials due to its controlled composition and phase purity. The antibacterial activity is attributed to the generation of reactive oxygen species (ROS) and the release of heavy metal ions, which disrupt bacterial cell structures. The nanocomposite's optical properties, including a bandgap of 4 eV, suggest its potential for photocatalytic applications and electronic devices. The study also discusses the significance of the nanocomposite's structure and composition in determining its properties, emphasizing the importance of optimizing synthesis conditions to enhance its performance.