
151Nanostructured MetalOxides andGas-Sensing Devices
Using nanoparticle thin lms for sensing applications is a promising
method to improve the response time and the sensitivity of the sensors
[256]. The sensing mechanism of nanoparticles with respect to CO and NO
measurements is attributed to interactions between different species on
the particle surface. It has been established that both gases react with pre-
adsorbed oxygen or oxygen from the lattice sites, and release free electrons
into the conduction band thus bringing an appreciable change in the elec-
trical conductivity of the sensing material. This change in t