Multifunctional biogenic ZnO/Fe₃O₄ nanocomposites for environmental remediation and breast cancer therapy

Breast cancer remains one of the leading causes of cancer-related mortality among women worldwide, highlighting the need for efficient and targeted therapeutic platforms. In this study, ZnO/Fe₃O₄ nanocomposites were successfully synthesized via a green route using Ulva pertusa seaweed extract and investigated for photocatalytic, antibacterial, and cytotoxicity properties. The novelty of this work lies in evaluating the effect of Fe₃O₄ incorporation on the structural, magnetic, photocatalytic, and biological properties of ZnO/Fe₃O₄ nanocomposites. The synthesized nanocomposites were explored as multifunctional magnetically recoverable nanocarriers with potential therapeutic activity against MCF-7 breast cancer cells. Structural characterization confirmed the successful formation of nanocomposites with crystallite sizes decreasing from 18.58 to 14.14 nm as the Fe₃O₄ content increased. Photocatalytic investigations revealed that ZnO/Fe₃O₄(1–3) exhibited the highest degradation efficiency of 97.80%. Cytotoxicity evaluation was performed using MTT assays against MCF-7 cells, where ZnO/Fe₃O₄(1–5) demonstrated the strongest cytotoxic effect and its IC 50 analysis is reported approximately 57.8% to 2.3%. The synthesized nanocomposites exhibited antibacterial activity against both Escherichia coli and Staphylococcus aureus , with slight variations in antibacterial performance depending on the ZnO/Fe₃O₄ composition. Overall, these green-synthesized ZnO/Fe₃O₄ nanocomposites represent multifunctional and magnetically responsive platforms with promising potential for environmental remediation and biomedical applications.