BioFETs operate on the principle of field-effect modulation. A biological recognition element, such as an antibody or DNA aptamer, is immobilized on the gate surface of a traditional FET. When the target analyte binds to the recognition element, it causes a change in the surface charge. This change modulates the electric field across the transistor's channel, leading to a measurable variation in the current. This specific interaction allows BioFETs to detect even low concentrations of biological substances.
