School of Precision Instruments and Opto-Electronics Engineering, Tianjin University, Tianjin 300072, China.
School of Engineering, University of Warwick, Coventry CV4 7AL, UK.
Biosensors (Basel). 2022 Aug 14;12(8):639. doi: 10.3390/bios12080639.
Liquid crystals (LCs) have been widely used as sensitive elements to construct LC biosensors based on the principle that specific bonding events between biomolecules can affect the orientation of LC molecules. On the basis of the sensing interface of LC molecules, LC biosensors can be classified into three types: LC-solid interface sensing platforms, LC-aqueous interface sensing platforms, and LC-droplet interface sensing platforms. In addition, as a signal amplification method, the combination of LCs and whispering gallery mode (WGM) optical microcavities can provide higher detection sensitivity due to the extremely high quality factor and the small mode volume of the WGM optical microcavity, which enhances the interaction between the light field and biotargets. In this review, we present an overview of the basic principles, the structure, and the applications of LC biosensors. We discuss the important properties of LC and the principle of LC biosensors. The different geometries of LCs in the biosensing systems as well as their applications in the biological detection are then described. The fabrication and the application of the LC-based WGM microcavity optofluidic sensor in the biological detection are also introduced. Finally, challenges and potential research opportunities in the development of LC-based biosensors are discussed.
液晶（LC）已被广泛用作敏感元件，基于生物分子之间的特定键合事件会影响 LC 分子的取向这一原理，构建 LC 生物传感器。根据 LC 分子的传感界面，LC 生物传感器可分为三种类型：LC-固界面传感平台、LC-水界面传感平台和 LC-液滴界面传感平台。此外，作为一种信号放大方法，LC 与 whispering gallery mode（WGM）光学微腔的结合由于 WGM 光学微腔的极高品质因数和微小模式体积，可以提供更高的检测灵敏度，从而增强了光场与生物靶标之间的相互作用。在本综述中，我们概述了 LC 生物传感器的基本原理、结构和应用。我们讨论了 LC 的重要性质和 LC 生物传感器的原理。然后描述了生物传感系统中 LC 的不同几何形状及其在生物检测中的应用。还介绍了基于 LC 的 WGM 微腔光流传感器的制造和在生物检测中的应用。最后，讨论了基于 LC 的生物传感器发展中的挑战和潜在的研究机会。
