Development of a novel NIR viscosity fluorescent probe for visualizing the kidneys in diabetic mice

We report a novel probe that can visualize the distinction diabetic kidney from normal kidney for the first time by monitoring changes in cell viscosity. The synthesis method of NI-VD is simple and feasible. The large Stokes’ shift, near-infrared emission peak, and specific response imply that NI-VD can monitor changes in mitochondrial viscosity at the cell, organ, and organism level. NI-VD is a new solution for the diagnosis and treatment of diabetic nephropathy. [Display omitted] •NI-VD visualized and proved the distinction diabetic kidney for the first time.•NI-VD has maximum emission peaks at 730 nm with a large Stokes-shift.•NI-VD can accurately target with mitochondria.•NI-VD can detect changes in viscosity in a complex cellular environment. Viscosity is an important parameter for evaluating cell health, and abnormal viscosity can cause a variety of intracellular organelle function disorders. The mitochondria are a key organelle in cells, and the viscosity of the mitochondria determines the state of the cell. In this work, we report a novel near-infrared fluorescent probe, referred to as NI-VD, that has a large Stokes-shift and a satisfactory response multiple. NI-VD can sensitively detect changes in cell viscosity in cells and tissues, and it can effectively avoid interference from the overlap of excitation and emission light. The fluorescence spectrum shows that NI-VD has maximum emission peaks at 730 nm, and the fluorescence intensity is amplified with an increase in the solution viscosity. The response from pure PBS solution to glycerol changes by 13-fold. After confirmation in a variety of cell and biological models, NI-VD can detect the changes in viscosity in mitochondria. Most importantly, this study is the first to visualize the differences between the kidneys of diabetic mice and normal mice. This approach is a new solution for the diagnosis and treatment of diabetic nephropathy.