Research on Competitive Enzymatic Hydrolysis-Assisted Liquid Crystal-based Acetylcholine Sensor

Abstract

1. 报道了一种基于液晶的简单、低成本、无标记的检测乙酰胆碱的方法。 2. 氯化十四酰胆碱与乙酰胆碱发生竞争性的酶解反应，引起液晶分子在界面上的排列方式及液晶的光学形貌发生了改变。 3. 乙酰胆碱的检测限低至14.5 nmol/L。 4. 基于液晶实现了对乙酰胆碱高灵敏度、高特异性的检测。 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. A simple, low-cost and label-free assay was reported for detection of acetylcholine (ACh) based on liquid crystals (LCs). Variations in the arrangement and optical appearance of LCs are due to the competitive enzymatic hydrolysis between myristoylcholine (Myr) and ACh by acetylcholinesterase (AChE). By using this strategy, highly sensitive and highly specific detection of ACh is achieved.