The study reports the synthesis and characterization of a Fe₂O₃–CuO–CuFe₂O₄ nanocomposite using the sol-gel method, with ethanol as a reactive fuel. X-ray Diffraction (XRD) confirmed the presence of Fe₃O₄, CuO, and CuFe₂O₄ phases, with an average crystallite size ranging from 60 to 95 nm. UV–visible spectroscopy revealed an energy bandgap of approximately 4 eV, indicating potential optoelectronic applications. Scanning Electron Microscopy (SEM) images showed a porous and heterogeneous aggregation of particles. The nanocomposite exhibited antibacterial activity against gram-positive *Staphylococcus aureus* with a maximum zone of inhibition (ZOI) of 9 mm, but showed no inhibitory effect against gram-negative *Escherichia coli*. The antibacterial mechanism is attributed to the generation of reactive oxygen species (ROS) and the release of heavy metal ions. The study highlights the potential of the Fe₂O₃–CuO–CuFe₂O₄ nanocomposite for optoelectronic devices and therapeutic applications.The study reports the synthesis and characterization of a Fe₂O₃–CuO–CuFe₂O₄ nanocomposite using the sol-gel method, with ethanol as a reactive fuel. X-ray Diffraction (XRD) confirmed the presence of Fe₃O₄, CuO, and CuFe₂O₄ phases, with an average crystallite size ranging from 60 to 95 nm. UV–visible spectroscopy revealed an energy bandgap of approximately 4 eV, indicating potential optoelectronic applications. Scanning Electron Microscopy (SEM) images showed a porous and heterogeneous aggregation of particles. The nanocomposite exhibited antibacterial activity against gram-positive *Staphylococcus aureus* with a maximum zone of inhibition (ZOI) of 9 mm, but showed no inhibitory effect against gram-negative *Escherichia coli*. The antibacterial mechanism is attributed to the generation of reactive oxygen species (ROS) and the release of heavy metal ions. The study highlights the potential of the Fe₂O₃–CuO–CuFe₂O₄ nanocomposite for optoelectronic devices and therapeutic applications.