This book presents recent developments and fascinating attributes of electronic-nose (E-nose) technology based on advanced nanostructured materials that are compatible with modern semiconductor fabrication technology. The new trend in these nanostructured materials includes metal oxide nanostructures, 2D materials, graphene, and other carbon-based nanostructures. These versatile materials with remarkable electronic, mechanical, electrical, thermal properties, and potential e-nose in a wide range of fields are discussed in the book. Close attention is given to problems connected with stability, selectivity, and functionalizing of e-nose devices and deposited materials. The field of sensors is indeed in fast and consistent growth.  This book consolidates information on each and every aspect of these novel materials, their gas sensing mechanisms, engineering, and e-nose devices covering the entire spectrum of up-to-date literature citations, current market, and patents in a very detailed manner. Moreover, in the past few years, tremendous advances have been made in experimental and theoretical studies on various properties of these materials. In summary, this book makes an attempt to provide in-depth study of recent advances and focuses on current problems related to selectivity and stability of sensor devices. The book is interesting to all materials professionals and researchers from universities and national laboratories working in the field of nanostructured materials-based gas sensors.