  Metal-oxide sensors are widely used due to their sensitivities to different
types of gaseous, and these sensors are suitable for long-term applications,
even in the presence of corrosive environments. However, the microscopic
mechanisms with quantum effects, which are required to understand the gas-oxide
interactions are not well developed despite the oxide sensors potential
applications in numerous fields, namely, medicine (breath-sensors), engineering
(gas-sensors) and food processing (odor-sensors). Here, we develop a rigorous
theoretical strategy based on the ionization energy theory (IET) to
unambiguously explain why and how a certain gas molecule intrinsically prefers
a particular oxide surface. We make use of the renormalized ionic displacement
polarizability functional derived from the IET to show that the gas/surface
interaction strength (sensing sensitivity) between an oxide surface and an
isolated gas molecule can be predicted from the polarizability of these two
systems. Such predictions are extremely important for the development of health
monitoring bio-sensors, as well as to select the most suitable oxide to detect
a particular gas with optimum sensitivity.
