A gas detector utilizing tunnel junction geometry is disclosed. The gas detector comprises a first electrically conductive material layer, an electrically nonconductive material layer disposed on the first electrically conductive material layer, a second electrically conductive material layer disposed on the electrically nonconductive material layer, a gas source (34) in fluid communication with the second electrically conductive material layer; and a power source in electrical communication with the first and second electrically conductive material layers. A method of detecting a gas utilizing the detector of the present invention is also disclosed. A method of making a gas detector is likewise disclosed.