Selective detection of benzene traces at room temperature using metal decorated carbon nanotubes

Hybrid materials consisting of oxygen plasma treated multiwalled carbon nanotubes (MWCNTs) decorated with four different metal nanoparticles can be tailored for the recognition of benzene vapors with high sensitivity and selectivity. The plasma treatment enables cleaning, activating, functionalizing and metal decorating carbon nanotubes in a single step. Metal nanoparticles transfer significant amount of charge upon adsorption of a target molecule, so as to affect electron transport in the nanotube. When combined in a microsensor array operating at room temperature, the use of benzene-sensitive and benzene-insensitive metal-decorated multiwalled carbon nanotubes can provide selective detection of benzene at trace levels (i.e., detection limit below 50 ppb.