Detecting chemical, biological, and explosive agents

The detection and measurement of chemical, biological, and explosive agents is becoming more important and receiving much greater emphasis within the optics, military, and international communities. The choice of detection technique depends on the agent being sought, expected background interferences, and whether point samples or stand-off ranges are required. Many current and developing techniques employ optical and laser spectroscopic sensing, or include conventional analytical chemistry systems based on mass spectrometry or gas chromatography. Optics generally plays the role of ‘enabling technology’ in these systems, as defined in the 1998 National Research Council report, Harnessing Light: Optical Science and Engineering for the 21st Century. For example, optical spectroscopy is familiar as a tool for chemical species identification based on absorption, Raman, or fluorescence spectra. However, many are not aware of its widespread use in commercial medical tests, such as blood analysis, to analyze specimens. In the following, I expand on this theme, and present an overview of some emerging technologies and research challenges in the detection of chemical, biological, and explosive agents.1–7