Chemical sensor analysis

Chemical sensors are devices which incorporate a chemical recognition element which is in intimate contact with a transducer, the aim of which is usually to provide a digital electronic signal. Such devices are usually operated continuously, to provide a real time analysis of a specific chemical, or group of chemicals. It is also possible to use these devices to make one-shot, spot checks, or to incorporate them into instrumentation such as flow-injection analysers, or automated multi-analysers. The recognition element is the key feature of chemical sensors and may be an inorganic or organic compound or of biological origin. In the latter case, the devices are termed biosensors. The use of biological components has created considerable interest due to the often very high selectivities of these materials for their target analytes. Examples of these recognition components are discussed as well as some sensor types: ion selective electrodes, ISFETs, amperometric sensors, optical chemical sensors