Spatiotemporal visualization of superoxide in diabetic nephropathy via an activatable fluorescent probe

Diabetic nephropathy (DN) is a serious complication of diabetes mellitus (DM), characterized by progressive renal impairment and limited biomarkers for early diagnosis. Herein, we developed CZY, a mitochondria-localizing activatable fluorescent probe for superoxide anion (O₂^·-). CZY showed high selectivity toward O₂^·-, chemical stability, and favorable biocompatibility. In mIMCD-3 cells, CZY enabled time-dependent visualization of O₂^·--associated oxidative activity. Additionally, CZY could enable visualization of O₂^·- and support it as an effective molecular imaging platform for monitoring O₂^·- variation in DN model. Collectively, this study clarifies oxidative stress level in DN and provides a useful basis for subsequent diagnostic and therapeutic exploration.