Substituted Phthalocyanine-Based Nanostructured Materials for Room-Temperature Gas Sensing Applications

In recent years, environment monitoring is one of the prerequisites for the welfare of human beings. Environment monitoring leads to the development of sensors that can detect the presence of harmful/toxic gases and vapours. For the detection of poisonous gases, various studies have been reported over the last few years using nanostructured thin films based on various semiconducting oxides, conducting polymers and organic molecules. Among different organic materials, metallo-phthalocyanines (MPcs) based materials are regarded as excellent sensing material, as their electrical conductivity significantly changes on interaction with oxidizing/reducing gases. Sometimes small response characteristics of these sensors at room temperature become a limitation and can be overcome by exploring long-range molecular nanostructure with high surface/volume ratio. In this chapter, we have systematically discussed the development of cost-effective, highly sensitive and reproducible phthalocyanine-based room-temperature chemiresistive sensors capable of detecting harmful/toxic gases up to ppb levels. The primary emphasis will be laid on the formation of different phthalocyanine-based nanostructures, including nanowires, nanoflowers and nanobelts for sensing applications.