ONOO^--activated deep NIR-I fluorescent probe for visualization of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) refers to a clinicopathological syndrome. Its key feature is the abnormal accumulation of excessive fat within hepatocytes, and this condition occurs when factors like alcohol consumption and other specific causes of liver injury are excluded. With the improvement of living standards, the prevalence of NAFLD is on the rise annually as well. Thus, within the scope of this research, we designed and synthesized a deep NIR-I fluorescent probe (emission at 805 nm), named BDNOF-ONOO^-, based on a BODIPY fluorophore. This probe enables highly selective recognition of ONOO^-, which is abnormally expressed during the pathogenesis of NAFLD. This probe demonstrated remarkable advantages including rapid response, wide linear detection range, and strong resistance to interference from other reactive oxygen species, while its long-wavelength emission effectively avoided interference from tissue autofluorescence. Systematic validation at both cellular and animal levels confirmed the probe's capability for real-time dynamic monitoring of ONOO^- concentration fluctuations. Notably, BDNOF-ONOO^- enabled visualization of ONOO^- level variations through fluorescence signals in the liver tissues of NAFLD model mice. Eventually, BDNOF-ONOO^- successfully evaluated the therapeutic efficacy of hepatoprotective agents in NAFLD progression. This research provided an important methodological tool for in-depth investigation of NAFLD pathogenesis.