Electronic nose based on graphene, nanotube and nanowire chemiresistor arrays on silicon

Large arrays of cross-reactive sensor elements offer the ability to identify vapors from the signature response of the ensemble. We create an array of heterogeneous gas sensing microassemblies using dielectrophoretic assembly of various nanomaterials on silicon. Gas sensitive materials include reduced graphene oxide (rGO) platelets, single wall carbon nanotubes, and copper oxide nanowires. The array was exposed to a wide range of volatile organic compounds such as isopropyl alcohol, acetone, and aromatic compounds. The entire array was monitored to supply real-time resistance data from each sensor element. The chemiresistive assemblies show fractional resistance changes exceeding 150 percent upon introduction of volatile organic compounds. The use of cross-reactive, heterogeneous assemblies of diverse nanomaterials facilitates construction of an electronic nose.