Liquid Crystals in Analytical Chemistry: A Review

Nearing 130 years since their introduction, liquid crystals (LCs) have found diverse applications in different fields of science, including chemical analysis. This review encompasses the history of LCs, reviews various types of them, and presents their current applications in analytical chemistry. Since most applications of LCs in analytical chemistry are for the fabrication of biosensors, these applications are discussed first. The high sensitivity of LCs to changes in their environment makes them ideal for such sensors. Using them, analyte concentrations as low as 1 pM have been detected. Another major application of LCs is in gas chromatography (GC) as stationary phases, which is described in the second part of this review. Using LCs in GC leads to better separations, higher sensitivity, and improved selectivity. Such phases provide higher stability in elevated temperatures and increased column life times. Finally, applications of LCs in electro-analytical chemistry will be described briefly.