This is the first time a symposium focusing on the theme of chemical and biological defense has been organized as part of a ACS national meeting. The symposium brought together a large number of academic, government and industrial scientists. The work presented spanned concepts at incipientstage in the laboratory to developed systems that can be fielded in the immediate future. The book is probably the most comprehensive compilation of research being done in this field at this time.The papers incorporated in the book cover a wide range of methods to detect chemical and biological threats and also methods to protect against them. Consequently, the book is organized into the two main categories of detection and protection. The section on detection includes various approachesincluding cantilever and nanotube based methods, immunological approaches, infrared and fluorescence techniques, porous nano systems, Raman scattering methods, etc. The section on protection includes approaches based on nanoparticulates and nanofibers and new barrier and reactive materials.