Ultrasensitivity Detecting AChE through “Covalent Assembly” and Signal Amplification Strategic Approaches and Applied to Screen Its Inhibitor
Yongwei Zhao, Ao Shen, Xiaohui Hao, Mengwen Li, Lala Hou, Ziqi Li, Ruochen Duan, Man Du, Xue Li, Xuebin Wang, Xiuqing Zhao, Yunxu Yang
Abstract
An ultrasensitivity detecting assay for acetylcholinesterase (AChE) activity was developed based on "covalent assembly" and signal amplification strategic approaches. After hydrolyzing thioacetylcholine by AChE and participation of thiol in a self-inducing cascade accelerated by the Meldrum acid derivatives of 2-[bis(methylthio) methylene] malonitrile (CA-2), mercaptans triggered an intramolecular cyclization assembly by the probe of 2-(2,2-dicyanovinyl)-5-(diethylamino) phenyl 2,4-dinitrobenzenesulfonate (Sd-I) to produce strong fluorescence. The limit of detection for AChE activity was as low as 0.0048 mU/mL. The detection system also had a good detecting effect on AChE activity in human serum and could also be used to screen its inhibitors. By constructing a Sd-I@agarose hydrogel with a smartphone, a point-of-care detection of AChE activity was achieved again.