Development of a one-step synthesized red emission fluorescent probe for sensitive detection of viscosity in vitro and in vivo.

Diseases caused by metabolic abnormalities, such as inflammation and fatty liver, which are characterized by high viscosity, so it is necessary to detect the change of viscosity in vivo and in vitro. Due to the advantages of high sensitivity, noninvasive detection, high selectivity and real-time imaging, fluorescence imaging has become an effective means to detect biological parameters of biomolecules and life systems. Therefore, we have prepared a red emitting fluorescent probe NBI-V with easy synthesis which can ensure that the probe can be developed for the widely used to detection of viscosity changes in vivo and in vitro. The probe NBI-V has good stability, high response times, selectivity, and good biocompatibility. As the viscosity of a water-glycerol system increased from 1.29 cp to 937.48 cp, the fluorescence of NBI-V was increased by about 77 times. Biological experiments showed that the probe NBI-V can target mitochondria, and the Pearson correlation coefficient was as high as 0.89. What's more, it can distinguish normal liver from fatty liver, and can detect the viscosity changes caused by inflammation in mice.