There is a need for carbon dioxide sensors for a wide range of applications, including indoor air quality monitoring, alarm sensors in restaurants, breweries or around carbon dioxide tanks and in the food packing and storage industry where modified atmosphere packaging is used to increase the shelf like. In this project, a novel carbon dioxide sensor material is developed for use in resistive gas sensors. Some of the known carbon dioxide sensitive materials have high resistances. One of the aims of this project is to lower the resistance of the sensor materials to improve sensor performance.