Arsine gas sensor based on gold-modified reduced graphene oxide

A gas sensor was developed for arsine (AsH 3 ) which is the most toxic inorganic gas. The sensor was prepared from reduced graphene oxide (rGO), modified with a thin gold film, on an interdigitated array electrode. The conductance of the Au/rGO sensor was monitored in the presence of flowing AsH 3 that was prepared by reduction of aqueous arsenite with borohydride and vaporization of the hydride. Gas sensors fabricated with only rGO or Au did not exhibit AsH 3 sensitivity. However, rGO sensors combined with Au exhibited reversible conductivity enhancement with AsH 3 . The increase in conductivity probably occurred because the AsH 3 depleted adsorbed oxygen on the Au islands, resulting in the enhancement of hole conduction in the rGO film. Responses were observed for sub-ppmv levels of AsH 3 . The amounts of gold and rGO, the GO reduction, and the operating temperature were optimized to obtain a detection limit of 0.01 ppmv (determined from a signal level three times the baseline noise). Interference from other gases and vapors was examined. The sensor responded to NO 2 , but this is not expected to be present in air-quality-controlled clean rooms. AsH 3 is one of the most toxic chemicals used in the semiconductor industry, and the Au/rGO-based AsH 3 sensor is expected to have widespread applications.