ABSTRACT
A chemical sensor is a device that transforms chemical information, ranging from the concentration of a specic sample component to total compositional analysis, into an analytically useful signal. Chemical sensors typically contain two basic components that are connected in series: a chemical/molecular recognition system (receptor) and a physicochemical transducer. Biosensors are chemical sensors in which the recognition system functions via a biochemical mechanism (Figure 8.1) [1]. The biological recognition system translates information from the biochemical domain, usually an analyte concentration, into a chemical or physical output signal with a dened sensitivity. The main purpose of the recognition system is to provide the sensor with a high degree of selectivity for the analyte to be measured. While all biosensors are more or less selective (nonspecic) for a particular analyte, some are (by design and construction) only class-specic, since they utilize particular species of enzymes.
