Zhang_2022_Anal.Chim.Acta_1235_340540

Accurate detection of butyrylcholinesterase (BChE) activity is imperative to understand its biological function and diagnose related disease. Far-red (FR)/Near-Infrared (NIR) fluorescent probe with large Stokes shift for BChE detection is extremely important. In this study, we reported a new "off-on" FR/NIR fluorescent probe (DX-2) with large Stokes shift (110 nm). DX-2 was constructed through cyclopropionate to pull-push the optical tuable hydroxyl group of chloro-substituted dicyanoisophorone fluorophore. DX-2 ((ex)/(em) = 555/665 nm) featured high sensitivity (LOD0.08 U/mL) and selectivity, good pH practicability, low toxicity and good cell membrane permeability with a bright emission triggered by BChE. Furthermore, DX-2 exhibited good optical performance to image BChE activity in living cells. More importantly, the FR/NIR probe DX-2 was successfully applied to real-time monitor BChE in live tumor-bearing mouse model. These studies suggest that probe DX-2 has potential applicable value for detecting BChE in living biological systems and diagnosing BChE-related diseases.