Simple and Label-Free Liquid-Crystal-Based Detection of Acetylcholinesterase through Interactions between Liquid Crystals and Oil-in-Water Emulsion Droplets

Abstract

Here, we report a liquid crystal (LC)-based sensing method for the detection of acetylcholinesterase (AChE) and its inhibitor. The LC and glyceryl trioleate (GT)-in-water emulsion droplets were decorated with myristoylcholine chloride (Myr). The decoration helps to prevent the coalescence between the LC and GT emulsion droplets and therefore keeps the LCs in the nematic state, resulting in a bright optical image. In the presence of AChE, Myr was hydrolyzed, causing coalescence of LC and GT emulsion droplets, inducing the phase transition of LCs from the nematic to the isotropic state, resulting in a dark optical image. The biosensor exhibited a limit of detection (LOD) of 100 ng/mL. Moreover, the biosensor was highly specific for AChE and showed a high sensitivity for the detection of AChE inhibitor, with a LOD of 10 μg/mL. The biosensor is a simple and convenient sensing platform for the detection of AChE and its inhibitors. © 2021 Wiley-VCH GmbH