The electrical characterization of a multi-electrode odor detection sensor array based on the single SnO2 nanowire

The variation of electrical properties of individual SnO2 wedge-like nanowire along its length was characterized comparatively in a vacuum, low-pressure oxygen environment and in synthetic air mixed with various analytes. For characterization, a vapor–solid grown nanowire was indexed with multiple Pt mesoscopic contacts fabricated by e-beam induced deposition from Pt containing metalorganic precursor. The surface of the selected nanowire segments was functionalized with a catalyst via deposition of Pd nanoparticles. Detailed analysis of the electrical properties of the nanowire shows that the effective diameter of the conducting channel of the nanowire can be substantially modified along its length by the surface functionalization and nanowire width change. These variations of the electrical properties of nanowire segments are sufficient for reliable discrimination of acetone, 2-propanol, CO and hydrogen by this elemental multisensor array.