A biosensor is a device for the detection of an analyte that combines a biological component with a physicochemical detector component.

It consists of 3 parts:

• the sensitive biological element (biological material (eg. tissue, microorganisms, organelles, cell receptors, enzymes, antibodies, nucleic acids etc), a biologically derived material or biomimic) The sensitive elements can be created by biological engineering.
• the transducer in between (associates both components)
• the detector element (works in a physicochemical way; optical, electrochemical, thermometric, piezoelectric or magnetic.)

The most widespread example of a commercial biosensor is the blood glucose biosensor, which uses an enzyme to break blood glucose down. In so doing it transfers an electron to an electrode and this is converted into a measure of blood glucose concentration. The high market demand for such sensors has fueled development of associated sensor technologies.

Recently, arrays of many different detector molecules have been applied in so called electronic nose devices, where the pattern of response from the detectors is used to fingerprint a substance.

A canary in a cage, as used by miners to warn of gas could be considered a biosensor. Many of today's biosensor applications are similar, in that they use organisms which respond to toxins at a much lower level than us to warn us of their presence. Such devices can be used both in environmental monitoring and in water treatment facilities.

Applications

• Glucose monitoring in diabetes patients <-- historical market driver
• Remote sensing of airborne bacteria.
• Detection of pathogens
• Determining levels of toxins before and after bioremediation.

Links

• [http://www.biosensors.tk/ Biosensor research at Diepenbeek ].
• Latest developments in biosensors.