Diagnosis of Alzheimer’s Disease and <i>In Situ</i> Biological Imaging via an Activatable Near-Infrared Fluorescence Probe

Abstract

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 (<b>BChE</b>) 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 <b>BChE</b>. In this study, we developed a novel near-infrared fluorescent probe (<b><i>Chy-1</i></b>) for the detection of <b>BChE</b> activity. An excellent sensitivity, good biocompatibility, and lower limit of detection (LOD) of 0.12 ng/mL made the probe extremely specific for <b>BChE</b>, which was successfully used in biological imaging. What is more, <b><i>Chy-1</i></b> 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 <i>in situ</i> spraying. Most important of all, <b><i>Chy-1</i></b> was also successfully applied to track the <b>BChE</b> 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.