A novel turn-on near-infrared fluorescent probe for highly sensitive in vitro and in vivo detection of acetylcholinesterase activity

Acetylcholinesterase (AChE) is a key enzyme in the cholinergic pathway of the nervous systems, with its aberrant expression linked to various diseases. In this study, we have developed a novel Turn -On near -infrared fluorescent probe, TQ-AChE, for the sensitive and selective detection of AChE activity. Characterized by its near -infrared emission at 740 nm, TQ-AChE effectively overcomes the limitations of traditional fluorescent probes, such as short excitation wavelengths and limited tissue penetration, crucial for both in vitro and in vivo applications. The probe's low limit of detection (LOD) of 0.02 U/mL for AChE makes it highly sensitive, enabling rapid quantification of AChE activity in serum effectively. Cell imaging studies demonstrate that TQ-AChE can confirm higher AChE activity expression in normal liver cells compared to liver cancer cells. TQ-AChE can also monitor AChE fluctuations in APAP-induced acute effectively, facilitating the evaluation of the efficacy of liver detoxifying agents. Additionally, in vivo studies in mouse models validate the potential of the probe in real-time monitoring of AChE expression in liver injury. The ability of TQ-AChE to visualize AChE expression signifies its potential as a promising tool for early liver disease diagnosis and therapeutic monitoring, opening new possibilities in hepatological research and clinical diagnostics.