Diagnosis of Alzheimer's Disease and In Situ Biological Imaging via an Activatable Near-Infrared Fluorescence Probe.

Alzheimer's disease (AD) is a common neurodegenerative disease that makes the brain nervous system degenerate rapidly and is accompanied by some special cognitive and behavioral dysfunction. Recently, butyrylcholinesterase ( BChE ) was reported as an important enzyme, whose activity can provide predictive value for timely discovery and diagnosis of AD. Therefore, it is indispensable to design a detection tool for selective and rapid response toward BChE . In this study, we developed a novel near-infrared fluorescent probe ( Chy-1 ) for the detection of BChE activity. An excellent sensitivity, good biocompatibility, and lower limit of detection (LOD) of 0.12 ng/mL made the probe extremely specific for BChE , which was successfully used in biological imaging. What is more, Chy-1 can not only clearly distinguish tumor from normal cells but also forms a clear boundary between the normal and cancer tissues due to the obvious difference in fluorescence intensity produced via in situ spraying. Most important of all, Chy-1 was also successfully applied to track the BChE activity in AD mouse models. Based on this research, the novel probe may be a powerful tool for clinical diagnosis and therapy of tumor and neurodegenerative diseases.