Electrochemical sensors

Electrochemical sensors have been used extensively either as a whole or an integral part of a chemical and biomedical sensing element. For instance, blood gas (PO2, PCO2, and pH) sensing can be accomplished entirely by electrochemical means. Many important biomedical enzymatic sensors, including glucose sensors, incorporate an enzymatic catalyst and an electrochemical sensing element. The Clark type of oxygen sensor [Clark, 1956] is a well-known practical biomedical sensor based on electrochemical principles, an amperometric device. Electrochemical sensors generally can be categorized as conductivity/capacitance, potentiometric, amperometric, and voltammetric sensors. The amperometric and voltammetric sensors are characterized by their current-potential relationship with the electrochemical system and are less well-defined. Amperometric sensors can also be viewed as a subclass of voltammetric sensors.