Rong-hua Zhang, Qiongzheng Hu, Qi Kang
Feb 1, 2021
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Influential Citations
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Citations
Journal
Chinese Journal of Analytical Chemistry
Abstract
Abstract A simple, convenient and label-free approach was developed for detection of acetylcholine (ACh) based on competitive enzymatic hydrolysis by use of liquid crystals (LCs) as a sensing medium. Self-assembled monolayers of myristoylcholine (Myr) were obtained at the aqueous/LC interface when the surfactants were in contact with LCs, resulting in a perpendicular orientation of LCs at the interface. Thus, LCs displayed a dark optical image. However, enzymatic hydrolysis of Myr by acetylcholinesterase (AChE) disturbed the Myr monolayers, which led to a horizontal orientation of LCs at the interface, thereby inducing a dark-to-bright shift of the LCs optical appearance. Interestingly, as ACh was also a substrate of AChE, the bright appearance of LCs was prevented when incubating the mixture of AChE and ACh with Myr decorated aqueous/LC interface due to the competitive enzymatic hydrolysis between Myr and ACh by AChE. By using this strategy, ACh could be detected selectively and sensitively, with a broad linear range from 0.01 μmol/L to 1 mmol/L and a low detection limit of 14.5 nmol/L. The results showed that the competitive enzymatic hydrolysis-assisted LC-based sensor had potential applications in ACh detection.