  Chemical gas sensors based on nanowires can find a wide range of applications
in clinical assaying, environmental emission control, explosive detection,
agricultural storage and shipping, and workplace hazard monitoring. Sensors in
the forms of nanowires are expected to have significantly enhanced performance
due to high surface-volume ratio and quasi-one-dimensional confinement in
nanowires. Indeed, chemical gas sensors based on nanowires with a ppb level
sensitivity have been demonstrated. In this review, the fundamental aspects on
(i) methods of nanowire synthesis (ii) performance of nanowire sensors, (iii)
chemiresistors, transistor sensors, and their sensing mechanism, and (iv)
assembly technologies will be summarized and discussed. The prospects of the
future research on chemical gas sensors based on nanowires will be also
addressed.
