During the past few decades gas sensors have become more and more important in several domestic, urban, and industrial environments. The discovery of novel nano-structures provided ideal building blocks to fabricate a new generation of sensors that show significantly improved sensitivity and greatly reduced volume. The tiny size and dimensionality of nano-structures produce new properties (larger surface-to-volume ratio, higher reactivity, lower working temperature...) leading to better intrinsic performance. This book shows how metal oxide nano-structures and organic oligomers can be used to...