Abstract: The present invention is a fluorescent probe for detecting chemicals, particularly chemical warfare agents. The probe has a novel selection of polymers and fluorophores that allow for laser excitation and photodiode detection of chemical warfare agents. A probe based on poly(epichlorohydrin) as the polymer and nile blue A perchlorate as the fluorophore is sensitive to concentrations of mustard of less than 30 ppb. Probes based on fluoropolyol as the polymer and oxazine 170 perchlorate as the fluorophore is sensitive to low concentrations of soman. Selecting a cationic fluorophore that has an affinity for the chemical agent of interest and immobilizing that fluorophore in a polymer matrix provides a fluorescent probe capable of detecting the presence of the desired chemical agent in trace quantities. A set of probes may be used so that in the presence of an analyte or a mix of analytes one or more of the probes may be responsive.

Abstract: An instrument for total internal reflection fluorescence spectroscopy having modular probe that inexpensively monitors vapors and liquid-phase analytes under field conditions is described. The system is particularly helpful in evaluating multiple analytes using the fluorescence of a material immobilized in a thin sorbent polymer coating. At the same time, the system is capable of monitoring trace quantities of analyte using a fluorescence-read immunological reaction. The device includes a diode laser source, a shaped optical element (which may be as simple as a microscope slide), and one or more amplified photodiode detectors. The shaped optical element propagates light from the diode laser in a series of internally reflective bounces.

Abstract: The present sensor allows the user of any diode laser structure to be employed to provide sensitive chemical and biological detector. A diode laser electrochemical sensor is described in U.S. Pat. No. 5,591,407 “Laser Diode Sensor”. The present invention surpasses the capabilities of those sensors by measuring changes in the output power, output spectral characteristics or output signal auto-correlation function to detect the presence of chemical or biological films within the sensitive region.