Figure 3
From: Functionalization of an extended-gate field-effect transistor (EGFET) for bacteria detection

Equivalent circuit of the EGFET with a FET as transducer, the sensing area, and two SMUs including a voltage-source and an amperemeter. Area between FG and CG represents the liquid. D: Drain-electrode, S: Source-electrode, FG: Floating-gate electrode, CG: Control-gate electrode, RFG: Floating-gate resistor, UDS: Drain-source voltage, UCS: Control-gate-source voltage.