1. Development of ChemFET chemical field-effect transistors

At the initiative of P. Bergveld in the 1970s, the MOSFET transistor was adapted to liquid-phase detection, leading to the concept of the ChemFET (chemical field effect transistor) or ISFET (ion-sensitive field effect transistor) .

To achieve this, the metal gate electrode (G ) is replaced by an ion-sensitive insulator, and the gate is electrically biased through an electrolyte via a reference electrode (figure 1 ). By analogy with the operating principle of the MOSFET transistor...