Abstract
The invention discloses an FET-based sensor. The FET-based sensor according to an embodiment of the invention includes a substrate, an InN material layer, a source, and a drain. The InN material layer is formed over the substrate and has an upper surface. The upper surface thereon provides an analyte sensing region. The InN material layer serves as a current channel between the source and the drain. Thereby, ions adsorbed by the analyte sensing region induce a variation of a current flowing through the current channel, and the variation is further interpreted into a property of the analyte.