Measurement and Applications: Electrochemical Sensors and Instruments: Main Characteristics and Applications

An electrochemical sensor is a device capable of providing analytical information about a sample, transforming the information associated with an electrochemical reaction into a signal that can be quantified. An electrochemical sensor is generally made up of three electrodes: a reference electrode that keeps the potential stable; a counter electrode that establishes a connection with the electrolyte solution; and a working electrode that functions as a transduction element in the reaction. Regarding the working electrode, it is important to underline that surface modification can be carried out by immobilizing functional groups or biological recognition elements, such as antibodies or enzymes, so that the species of interest can be electrochemically detected. In recent decades, sensors have benefited from advances in microelectronics and microengineering, with the manufacture of smaller sensors, greater sensitivity and selectivity, larger dynamic range and lower production costs, and electrochemical sensors are not an exception. Thus, electrochemical sensors are being increasingly used in a large number of applications due to their ability to be easily integrated into automatic measurement systems that work in the laboratory or outdoors, which is the case when they are used for environmental parameters assessment.