The present invention is directed to a multiwire nanowire field effect transistor (nwFET) device for the measurement. The device includes a sensing nanowire having a first end and a second end and a nanowire FET having a first end and a second end, wherein the first end of the sensing nanowire is connected to the nanowire FET to form a node. Additionally, the first end of the nanowire FET is connected to a source electrode, the second end of the nanowire FET is connected to a drain electrode, and the second end of the sensing nanowire is connected to a base electrode. The sensing nanowire is derivatized with a plurality of immobilized capture probes that are specific for a target(s) of interest. The device is used to detect biomolecules or to detect the change in the ionic environment of a sample. In a further embodiment, the sensing nanowire is derivatized with amino, carboxyl or hydroxyl groups. Upon a change in ionic environment, or binding of a molecule to the sensing nanowire, the sensing nanowire current (IB) fluctuates. This fluctuation is amplified and readout as the nanowire FET drain current (ID). Accordingly, the present invention provides for label-free detection of biomolecules and may find use as a point-of-care diagnostic device.