Effortless and controllable electrical amplification in single-PMOS sensor for chemical and biological sensing

We report an effective nonlinear readout body-coupled modulation strategy that enables electrical amplification of sensitivity in a single p-channel metal-oxide semiconductor (PMOS) field-effect transistor (FET). The threshold voltage exhibits a quadratic dependence on the body potential (V_B) by dynamically biasing the body terminal instead of the gate, thus providing an extra electrical amplification from the intrinsic electrochemical surface potential changes. Implemented on a commercial PMOS with a TiN extended electrode here, this architecture achieves apparent V_B-amplified sensitivity up to 1200 mV/pH, over twentyfold enhancement, without any additional circuit or process complexity. The p-channel configuration is crucial, as its less body-effect coupling and hole-dominated conduction enhance the interfacial response far beyond its n-type counterpart. The same body-coupled response also amplifies biomolecular recognition signals such as DNA hybridization, suggesting a transistor-level electrical amplification mechanism for chemical and biological sensing possibilities. This work introduces a minimalistic yet powerful approach that transforms conventional p-channel FETs into ultra-sensitive electrochemical transducers, establishing a scalable pathway toward high performance sensors. This is an ultra-low-cost route to achieving controllable high sensitivity, which offers an efficient amplification strategy over conventional approaches in field-effect sensors.