Highly sensitive H₂O₂ colorimetric sensing in tumor cells via stable phospholipid-coated CsCu₂I₃ peroxidase-like nanoenzyme

Highly sensitive and rapid detection of hydrogen peroxide (H₂O₂) associated with tumor cells is potentially valuable for cancer-related bioanalysis and therapeutic evaluation. However, it remains challenging to develop colorimetric sensing materials that are simultaneously sensitive, selective, stable and fast under physiological conditions. Metal halide perovskites have attracted attention for colorimetric sensing due to their tunable bandgap structures and enzyme-mimicking catalytic properties, yet the development of non-toxic and biocompatible perovskite-based colorimetric platforms is still limited.

Here, we report phospholipid membrane (PM)-coated CsCu₂I₃ nanocrystals (PM-CsCu₂I₃ NCs) as a stable and biocompatible peroxidase-mimic nanozyme for H₂O₂ detection. PM-CsCu₂I₃ NCs enable colorimetric H₂O₂ sensing with a detection limit of 14 μM in solution. DMPO spin-trapping EPR measurements further confirm that hydroxyl radicals (•OH) are generated through a Fenton-like process, and the platform enables discrimination of tumor cells from normal cells based on endogenous H₂O₂-related responses. In addition to short-term biocompatibility, the nanozyme shows favorable long-term cytocompatibility and hemocompatibility, and exhibits concentration-dependent antitumor activity in vitro via oxidative-stress-associated effects, suggesting potential to integrate detection with chemodynamic therapy.

Overall, these findings expand the application scope of biocompatible, lead-free perovskite nanozymes for H₂O₂-associated bioanalysis and related theranostic exploration.