Diode Laser-based Biosensor for Detection of Biological Warfare Agents

The need for simple and practical instrumentation for rapid identification and detection of biological agents has been recognized as an important research area in sensor development. Specific antibody/antigen binding, in conjunction with evanescent wave excited fluorescence sensing, has been applied to the detection of toxins and chemical and biological warfare materials. However, there remains a need to develop a reliable, highly sensitive and lightweight instrument capable of performing immunoassays of toxins or infectious disease agents in war zones, to monitor decontamination procedures or to detect traces of biological agents for treaty verification. This proposal suggests the development of a compact, diode laser-based biosensor that can be used in war zones and in compliance monitoring. The innovation of the proposed system is the combination of sensitive diode laser-based methods of excitation with near-infrared saturable absorber-tagged immunological or DNA hybridization probes to provide a sensor having unparalleled sensitivity to biological warfare agents and toxins. The Phase I technical objectives include selection of label materials, design and fabrication of the diode laser-based instrumentation, immobilization of fluorophores on waveguide structures, fabrication of modular photodetection elements and electronic components, and acquisition of families of test data for use in optimization of a proof-of-concept prototype system.