Mitochondria-Targeted Fluorescent Probe for Super-Resolution Imaging of HNO in Lung Cancer

Lung cancer is a leading cause of cancer-related mortality globally, with complex biochemical processes underlying its initiation and progression. Nitroxyl (HNO), a reactive nitrogen species with unique chemical and biological properties, has emerged as a potential regulator of tumor biology. However, the transient nature and intertwined pathways of HNO with nitric oxide (NO) pose significant challenges for precise, real-time detection at the subcellular level, particularly within the mitochondrial key sites where HNO is generated and utilized. Herein, a mitochondria-targeted fluorescent probe (DCPH) was designed and synthesized for the super-resolution imaging of HNO. DCPH demonstrates high sensitivity and selectivity for HNO, with stable performance across the physiological pH range. Super-resolution imaging confirms the mitochondria-targeting capability of DCPH, which enables the visualization of both exogenous and endogenous HNO in A549 cells. This probe is capable of successfully monitoring HNO dynamics under inflammatory stimulation and during NO/H₂S crosstalk. Furthermore, in vivo imaging in tumor-bearing mice demonstrates that DCPH can visually track HNO production during sodium nitroprusside (SNP) treatment, which is correlated with significant tumor growth inhibition. Overall, DCPH provides a novel tool for the high-resolution detection of mitochondrial HNO and offers insights into the biological functions of HNO in cancer.