Applicants have produced a chromophore and a polymer that are highly sensitive to the presence of various agents, including organophosphates, pesticides, neurotoxins, metal ions, some explosives, and biological toxins. The detection is accomplished by detecting a change in the fluorescence characteristics of the chromophore or polymer when in the presence of the agent to be detected. The chromophore and polymer may be incorporated into sensors of various types, and they are adaptable for potential field use in areas where detection of these types of agents is desired.