Graphene FET Biosensor Based on the Concanavalin A

Concanavalin A (ConA) is a particular protein that can specifically bind to various sugars, glycoproteins, and some structures of glycolipids (mainly internal and non-reducing terminal α-D-mannosyl and α-D-glucosyl groups). Unlike the other biological interactions mentioned above, ConA protein only specifically adsorbs target with glycosyl groups such as monosaccharides, glycans, glycoproteins, cell surface with glycosyl groups, etc. This allows the interaction between ConA and targets (with glycosyl groups) to be described separately as a special type of biological interaction. In actual biomedical clinical detection applications, glycoproteins, cell surfaces, microbial surfaces, virus surfaces, etc., all contain glycosyl groups, which makes it possible to use ConA protein for specific detection. This chapter introduces the graphene field-effect transistor biosensor combined with ConA for rapid detection of targets contained glycosyl groups. Then discusses two different detection modes that are adsorption mode detection and dissociation mode detection. Unlike the biological interactions described previously, ConA protein has a wide range of glycosyl group binding ability, which makes it possible to use ConA in many glycosyl group-containing targets. But at the same time, it should be noted that the binding of ConA to targets is not one-to-one, so competitive adsorption issues should be considered in practical applications.