Oxygen (O2) is an essential gas not only for us and
most other lifeforms, but also for many industrial processes,
biomedicine, and environmental monitoring applications. Given the
importance of O2 and other gases, many researchers have focused on
developing and improving gas-sensing technologies. At the frontier
of this evolving field lie modern nanogap gas sensors—devices
usually comprised of a sensing material and two conducting
electrodes that are separated by a minuscule gap in the order of
nanometers (nm), or thousand millionths of a meter. When molecules
of specific gases get inside this gap, they electronically interact
with the sensing layer and the electrodes, altering measurable
electric properties such as the resistance between the electrodes.
In turn, this allows one to indirectly measure the concentration of
a given gas.
