Response Properties of the Gold Nanoparticle Sensors toward Benzene and Toluene Vapors

We present a novel room-temperature detection behavior of ligand-encapsulated gold nanoparticle sensors toward benzene and toluene. The nanoparticle sensors were observed to detect 1 ppm of toluene. Excellent reproducibility and dynamic range were obtained at least up 100 ppm concentration of toluene. Equilibrium response was observed within three seconds. The nanoparticle sensors were observed to be able to differentiate between benzene and toluene, which are very similar in their structures with one methyl difference. Moreover detection properties were easily modified by simply using two different ligand molecules on the gold surface. Although much progress has been made in gas sensors due mainly to recent interests in nano-materials, the integrate enhancement in sensing properties has rarely been reported. Such integrate sensing properties of the nanoparticle can make a promising candidate materials for applications in electronic noses as well as gas sensors in in-door air quality monitoring.