The fusion of basic ideas in mathematics, biology, and chemistry with ongoing improvements in hardware and computation offers the promise of much more sophisticated and accurate sensing capabilities than currently exist. Coupled with the dramatic rise in the need for surveillance in innumerable aspects of our daily lives brought about by hostile acts deemed unimaginable only a few short years ago, the time is ripe for scientists in the diverse areas of sensing and security to join together in a concerted effort to combat the new brands of terrorism.