The interactions between proteins and nanoparticles need to be fully characterized as the immobilization of proteins onto various nanoplatforms in the physiological system often results in the change of surface of the protein molecules to avoid any detrimental issues related to their biomedical applications. Hence, in this article, the successful low-temperature synthesis of a BP-based γ-Fe₂O₃ (IB) nanocomposite and its interactive behavior with bovine serum albumin (BSA)—a molecule with chemical similarity and high sequence identity to human serum albumin—are described. To confirm the formation of γ-Fe₂O₃ and the IB nanocomposite, X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy analyses of the materials were performed. Additionally, the physical interaction between BSA and the IB nanocomposite was confirmed via UV–Vis and photoluminescence spectral analyses. Finally, the biocompatibility of the BSA-immobilized IB nanocomposite was verified using an in vitro cytotoxicity assay with HCT-15 colon cancer cells. Our findings demonstrate that this newly developed nanocomposite has potential utility as a biocompatible nanoplatform for various biomedical applications.