What is "bio-fet"

Field effect transistor based biosensor (Bio-FET) is a field-effect transistor that is gated by biological molecules. When biological molecules bind to the FET gate they can change the gate charge distribution resulting in a change in conductance of the FET channel. A Bio-FET consists of two main compartments: one is the biological recognition element and the other is the field effect transistor (e.g. ISFET).