The first scientifically proposed as well as successfully commercialized biosensors were those based on
electrochemical sensors for multiple analytes. Electrochemical biosensors have been studied for a long
time. Currently, transducers based on semiconductors and screen printed electrodes represent a typical
platform for the construction of biosensors. Enzymes or enzyme labeled antibodies are the most common
biorecognition components of biosensors. The principles of, and the most typical applications for
electrochemical biosensors are described in this review. The relevant systems are divided into three types
according to the operating principle governing their method of measurement: potentiometric,
amperometric and impedimetric transducers, and the representative devices are described for each group.
Some of the most typical assays are also mentioned in the text.