Polyelectrolytes functionalized nematic liquid crystal-based biosensors: An overview

• Applications of Polyelectrolytes (PEs) functionalized-liquid crystals (LCs) for biosensors are narrated.
• Various methods for functionalization are described.
• Their use for various kinds of biosensors is discussed.

The liquid crystalline state of matter arises from orientation-dependent and non-covalent interactions between molecules within condensed phases. Because the balance of intermolecular forces that underlies the formation of liquid crystals (LCs) is delicate, this state of matter can be easily perturbed by external stimuli in general, and therefore it has been applied to biosensors since the last two decades. LCs has been functionalized with polyelectrolytes (PEs) to obtain stability and specificity, and to facilitate the immobilization of enzymes, anti bodies, and ligands at the LC/aqueous interface. This review focuses on the LC/aqueous interface functionalized with various kinds of PEs that yield a fundamentally interesting and technologically promising class of interfaces, and their uses for chemical and biological sensing.