In Situ Multimodality Imaging of Cancerous Cells Based on a Selective Performance of Fe²⁺‐Adsorbed Zeolitic Imidazolate Framework‐8

Metal‐organic frameworks possess tremendous potential in biomedical areas for their particular structure. In this study, the authors explored Fe²⁺‐adsorbed nanoscaled zeolitic imidazolate framework‐8 (ZIF‐8) for in vivo multimodal imaging of cancerous cells for early diagnosis of target cancers. The observations demonstrate that adding Fe²⁺ into the suspension of ZIF‐8 can neutralize the alkalinity and lower toxicity, while the Fe²⁺‐adsorbed ZIF‐8 can readily transform to fluorescence ZnO and super paramagnetic Fe₃O₄ under the synergistic reaction of ROS, GSH, and acids. It is evident that the formation of the nanoclusters ZnO and Fe₃O₄ only occurred in cancerous cells and does not take place in normal cells, which can be attributed to the different ROS levels and specific micro‐environment in tumor and normal cells. This raises the possibility for the Fe²⁺‐adsorbed zeolitic imidazolate frameworks to act as promising agents for the in vivo multimodal imaging of cancers in their early stage.