A biosensor is an analytical device which converts a biological response into an electrical signal. It consists of 3 parts: the sensitive biological element, the transducer and the associated electronics or signal processors that are primarily responsible for the display of the results in a user-friendly way. The most widespread example of a commercial biosensor is the blood glucose biosensor. 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. There...