Chemical Sensors

CALVO ERNESTO; OTERO MARCELO

Piezoelectric transducer and applications, 2nd Edition

Springer Verlag

Lugar: Berlin, Heidelberg; Año: 2008; p. 241 - 257

We are surrounded by a complex environment and therefore need to monitoraspects of this environment in real time in connection with pollution, health and safety, etc. Like the human senses of olfaction, sight, touch, hearing and taste link us with the external world, chemical sensors allow us to monitor and record the chemical variables of the external environment in the same way we monitor temperature, pressure, etc. A chemical sensor is a device which responds to a particular analyte molecule in a selective way in the presence of other molecules through a chemical reaction and can be used for the qualitative and quantitative determination of the analyte in the complex sample. After recognition of a molecular entity, the chemical sensor transduces the signal through a physicochemical process into an electrical signal which can be further amplified and processed. While Chap. 2 deals with different types of acoustic transducers, this tutorial focuses on the chemical sensing layer that affects the molecular recognition and the different transducers that can be employed. Different types of chemical sensors include different transducing methods to obtain processable electrical signals, so we have a variety of chemical sensors: 1. Electrochemical (potential, current or conductivity). 2. Optical (optical waves). 3. Mass sensitive (acoustic wave sensing). 4. Heat (calorimetric). 5. Magnetic.