Overview of enzyme based biosensors and their applications

Enzymes are biocatalysts that govern life processes. Each biochemical reaction of cell metabolism is catalyzed by one specific enzyme. Enzymes can catalyze reactions in different states but most commercial enzymes, being water soluble are difficult to recover at the end of the catalytic process. This restricts the use of soluble enzymes to essentially batch-operations followed by disposal of these expensive enzymes containing solution. A possible approach to resolve this problem is to attach enzymes onto a solid/semi solid support material. Such an attachment restricts the free movements of the enzyme molecules and renders them insoluble in aqueous media. The process of attachment of enzymes on an insoluble solid/semisolid material by physical or chemical bonding known as immobilization. In the present review we have discussed in brief about the enzyme-based biosensors, their history of development, classification and their applications in various filed with special emphasis on medicine and analytical assays.