A number of faculty members have programs that center on the mode of action of, and detection of, toxicants and entities relevant to homeland security. These efforts focus on the several general areas. Projects centered on analytical methodologies include development of new methods of detection of toxins, pollutants and their metabolites in environmental and biological matrices and the development of nanomaterials and fabrication of nanostructures and associated techniques for ultra-sensitive detection of toxins, explosives and metabolites intracellularly and in complex matrices. Groups also work on molecular aspects of these problems including study of the organic chemistry of toxins, particularly carcinogens, their mechanisms of toxication and molecular defenses against toxin assault. These studies entail generation and characterization of reactive intermediates derived from toxic agents and the DNA adducts derived from carcinogens. There are also efforts to generate structure-activity relationships among toxins and anti-toxins.