ABSTRACT

A biosensor is a compact sensing device that incorporates a specific biological or biomimetic element connected to, or integrated within, a physicochemical transducer or a transducing microsystem. One can say that biosensors are the technological counterpart of our sense organs, combining the recognition with a biological recognition element by a transducer. The sensitivity, reliability, and usefulness of biosensors are determined by the stability of the immobilization techniques. A bioreceptor is a biological molecular species or a biological system that adopts a biochemical mechanism for analyte recognition. Enzyme-based biosensors are molecular biosensors relying on specificity and selectivity of an enzymatic protein toward a target substrate. Enzymes were immobilized on polymer films such as polyacrylamide hydro-gels, polyvinylchloride, or polyurethane, yielding active sensing devices. Oriented immobilization of antibodies onto the gold-coated biosensor surface is often realized by using self-assembled monolayers with thiol groups.