Liquid crystals: Emerging materials for use in real-time detection applications

With the rapid advances in liquid crystal (LC) material technology over recent decades, many different practical devices have been developed and commercialized. LC devices have found numerous applications in fields such as imaging, microscopy, spectroscopy, and optical probing. Multifarious LC-based sensors have been developed to analyze label-free polyelectrolytes, ions, molecules, and biological systems. The detection principle of these LC sensors is based on the highly sensitive orientational response of LC molecules to minute changes in surface structures. Moreover, due to their potential applications in fields such as chemistry, biomedicine, and environmental science, scientists have been attracted to the research and development of LCs because of their potential use in real-time sensors. This review presents a brief overview of the historical background on the research progress of LCs and recent trends in their use in real-time detection applications.