Patent ID: 7394118

Claim:
A chemical sensing device, comprising: a length of a semiconductor metal oxide material nanowire, having a diameter which is less than 30 nm; a semiconductor oxide layer on which the nanowire is located; a drain contact formed on the semiconductor oxide layer to be in contact with one end of the nanowire; a source contact formed on the semiconductor oxide layer to be in contact with another end of the nanowire; a semiconductor substrate on which the semiconductor oxide layer is formed, wherein the semiconductor substrate, the drain contact, the source contact, the oxide layer and the nanowire for a field-effect transistor and the semiconductor substrate is a back gate; and a circuit element electrically coupled to the semiconductor substrate, the drain contact and the source contact to apply a control voltage on the semiconductor substrate back gate and to receive a current flowing through the drain contact, the nanowire and the source contact to effectuate an electrical connection and detection part, connected to said nanowire, said electrical connection being of a type that allows determination of at least two different adsorbed materials, that are adsorbed to said nanowire, by detecting its electrical characteristics, wherein the nanowire is structured to have an aspect ratio of at least 100:1 to enhance a gate dependence of the field-effect transistor.