ZnO Nanowire-Reduced Graphene Oxide Hybrid Based Portable NH<sub>3</sub> Gas Sensing Electron Device

A ZnO nanowire-reduced graphene oxide (ZnO-rGO) based portable ammonia (NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) gas sensing electron device working at room temperature has been demonstrated for the first time. The sensor is developed on a microelectrode of micro-electromechanical systems and supported by peripheral circuits and a hosting computer, which enables the real-time detection of NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> at room temperature. In contrast to the traditional sensors based on pure graphene or ZnO nanowires alone, the ZnO-rGO based gas sensing electron device can detect low-concentration (1 ppm) NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> with higher sensitivity (~7.2%). Besides, this sensor exhibits satisfying properties at sensing NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> with the concentration as low as 500 ppb at room temperature.