Sensitive ammonia gas sensors fabricated using biologically assembled copper sulfide

Copper sulfide-based ammonia (NH3) gas sensors were assembled using a genetically modified viral template. Glutamic acid residues on the filament-shaped bioscaffold surface facilitated the synthesis of nanocrystalline Cu1.8S. Each device comprised a network of biological materials decorated with a nonstoichiometric semiconductor. These chemiresistive devices had high sensitivity to NH3 concentrations from 10 to 80 ppm under room-temperature operation. Response times greater than 15 min were observed. These results demonstrate the potential of biotemplated materials for sensitive gas detection at room temperature. (C) 2014 The Japan Society of Applied Physics