Chemical gating experiment of a nano-field-effect transistor sensor using the detection of negative ions in air

We detected negative ions in air using a nano-field-effect transistor (nanoFET) sensor. We experimentally demonstrated that the concentration of anions in air could be detected by the conductance change of the field-effect channel induced by the chemical gating caused by the adsorption of charged particles on the gate surface of the nanoFET sensor. The characteristics of chemical gating - the operating mechanism of the nanoFET biosensor - were measured from the anion detection experiments in air. In this paper, we demonstrated the operating mechanism of chemical gating by measuring and analyzing both the conductance change and response characteristics of the nano-field-effect channel using the various anion concentrations in air.