Chemical sensors and methods of forming and making the same include an input terminal and an output terminal. A negative capacitance structure is configured to control a current passing horizontally from the input terminal to the output terminal, and has a first and second metal layer that are arranged vertically with respect to one another, and a ferroelectric layer positioned between the first and second metal layers. An electrode is in electrical contact with the negative capacitance structure, and is configured to change potential, to exceed a threshold, thereby triggering a discontinuous polarization change in the negative capacitance structure.