Silicon Nanowire Array Sensor for Highly Sensitive and Selective Detection of Nerve Agent Simulant Vapor via Surface Hydroxyl Groups

Silicon nanowire array with high density of hydroxyl groups is presented here to detect vapor of methylphosphonate (DMMP), a simulant of the high toxic nerve agent. The whole fabrication process of silicon nanowire array sensor device was highly compatible with CMOS technology. It was found that the current in nanowires array treated with plasma exhibited a large and reversible change when exposed to DMMP vapor. The silicon nanowire array sensor can easily and rapidly detect DMMP vapor with a detection limit down to 0.2 ppm, the highest sensitivity reported to date. These initial promising results provide opportunities for manufacture of ultra-sensitive and low-cost nanowire sensors for DMMP vapor detection.