Chen_2020_Anal.Biochem__113835

A reversible fluorescence probe for acetylcholinesterase activity detection was developed based on water soluble perylene derivative, N,N'-di(2-aspartic acid)-perylene-3,4,9,10-tetracarboxylic diimide (PASP). Based on the photo-induced electron transfer (PET), PASP fluorescence in aqueous is quenched after combining with copper ions (Cu(2+)). Acetylcholinesterase (AChE) is well known to catalyze the hydrolysis of acetylcholine (ATCh) to produce thiocholine, whose affinity is strong enough to capture Cu(2+) by thiol (-SH) group from the complex PASP-Cu, resulting in the fluorescence signal of PASP recovers up to 90%. This optical switch is highly sensitive depended on the coordination and dissociation between PASP and Cu(2+). We proposed its application for AChE activity detection, as well as its inhibitor screening. According to the change of fluorescence intensity, quantifying the detection limit of AChE was 1.78 mU.mL(-1). Classical inhibitors, tacrine and organophosphate pesticide diazinon, were further evaluated for drug screening. The IC(50) value of tacrine was calculated to be 0.43 muM, and the detection limit of diazinon was 0.22 muM. Both of these performances were much better than previous results, revealing our probe is sensitive and reversible for screening applications.