Triple-negative breast cancer (TNBC) is a highly malignant form of cancer, notorious for its limited treatment alternatives. Accumulating studies have revealed its susceptibility to ferroptosis, rendering ferroptosis inducers highly promising for the treatment of this cancer. This study aimed to evaluate the effect of a membrane-encased iron-sulfur nanoinducer (ISN) for the targeted treatment of TNBC. The ISN was developed with unique features combining enzyme-like activities and iron-releasing capabilities, functioning synergistically as a potent ferroptosis inducer. It exhibited dual enzymatic activities that synergistically promoted tumor cell death. The peroxidase-like activity of the ISN intensified oxidative stress in tumor cells, while its glutathione oxidase-like activity suppressed glutathione peroxidase 4 expression and depleted glutathione. Notably, the ISN demonstrated pH-responsive properties, selectively releasing Fe²⁺ in acidic conditions to further enhance the ferroptotic effects. These combined mechanisms enabled ISN to induce programmed cell death in TNBC cells through coordinated ferroptosis, autophagy, and apoptosis pathways. Furthermore, the biomimetic coating of the ISN with TNBC cell membranes improved tumor accumulation after intravenous injection and boosted antitumor efficacy in in vitro and in vivo models. These findings provide a potential approach for TNBC treatment using a multi-active ISN.

During criminal case investigations, blood evidence tracing is critical for criminal investigation. However, the blood stains are often cleaned or covered up after the crime, resulting in trace residue and difficult tracking. Therefore, a highly sensitive and specific method for the rapid detection of human blood stains remains urgent. To solve this problem, we established a nanozyme-based strip for rapid detection of blood evidence with high sensitivity and specificity. To construct reliable nanozyme strips, we synthesized CoFe₂O₄ nanozymes with high peroxidase-like activity by scaling up to gram level, which can be supplied for six million tests, and conjugated antibody as a detection probe in nanozyme strip. The developed CoFe₂O₄ nanozyme strip can detect human hemoglobin (HGB) at a concentration as low as 1 ng/mL, which is 100 times lower than the commercially available colloidal gold strips (100 ng/mL). Moreover, this CoFe₂O₄ nanozyme strip showed high generality on 12 substrates and high specificity to human HGB among 13 animal blood samples. Finally, we applied the developed CoFe₂O₄ nanozyme strip to successfully detect blood stains in three real cases, where the current commercial colloidal gold strip failed to do. The results suggest that the CoFe₂O₄ nanozyme strip can be used as an effective on-scene detection method for human blood stains, and can further be used as a long-term preserved material evidence for traceability inquiry.