Activatable fluorescent ratiometric probes for early diagnosis and prognostic assessment of acute kidney injury

Early and accurate diagnosis of acute kidney injury (AKI) is crucial for clinical treatment. However, most existing fluorescent probes are prone to background interference and limited renal targeting. We developed a ratiometric nanoprobe (RP-SC) that synergistically responded to H₂O₂ and targeted kidney injury molecule-1 (KIM-1). In AKI kidneys, RP-SC was hydrolyzed and slowly released encapsulated Hcy-BOH and Cy-Dopa. The H₂O₂ level was semi-quantitatively analyzed by fluorescence ratio (<i>F</i>_Hcy-BOH/<i>F</i>_Cy-Dopa). RP-SC exhibited prominent renal fluorescence in AKI mice, making it possible to accurately diagnose AKI and dynamically monitor renal function for up to 60 hours. RP-SC could monitor the process of AKI in vivo and provide an earlier warning of AKI than traditional strategies, subsequently evaluating the recovery of renal function after <i>N</i>-acetyl cysteine (NAC) treatment. Our study confirmed the ability of RP-SC for longitudinal monitoring of renal function in vivo by dual-targeting capacity, providing an effective tool for accurate diagnosis of early AKI while tracking the dynamic process of AKI treatment.