SBIR-STTR Award

We propose to develop a simple, portable, one-step assay for the detection of mycoplasma pneumoniae and influenza a which can be performed independent of a sophisticated laboratory by untrained or semi-skilled personnel. This simple, one-step method is called an optical bioassay (oba) and utilizes an inexpensive laser and photodetector to detect an antigen-antibody binding event. Antibody is covalently attached to a silicon surface and treated with a proprietary photolithographic technique to produce alternating rows of immunoreactive and non-immunoreactive antibody. When a narrow laser light beam is directed at the antibody coated silicon surface, the light is reflected at its incident angle without diffraction. When antigen binds to the immunoreactive (but not to the non- immunoreactive antibody) a biological grid is created. When light is directed at the reacted surface, the biological grid produces a diffraction signal which is easily detected with the intensity of the diffraction being proportional to the number of specific antigen-antibody events on the chip. Finally, the sophisticated but simple synthesis of microelectronics and biotechnology makes this immunodiagnostic system extremely portable and suitable for use in non-laboratory settings such as physician's office or field testing.

This is a continuation of our Phase I proposal for the diagnosis of natural and induced diseases of military using a novel optical biosensor assay (OBA) technology. OBA is one of the most innovative and promising new diagnostic technologies currently available. The technology uses the principle of optical diffraction for direct detection of antigen-antibody binding on a silicon chip. It can also be applied to other binding assays such as DNA probes.Techniques for activation of the silicon surface and immobilization of protein on the silicon surface have been developed during the Phase I feasibility study. We also demonstrated the feasibility of the biosensor assay with Hantaan Virus as a model analyte. In addition, a research prototype reader was also developed. In the Phase II study, we propose to further develop the technology into a practical system by scaling up the water manufacturing, improving the reproducibility, purifying the Hantaan Virus antigen, optimizing the OBA Hantaan Virus IgM and IgG assay, designing a panel assay, adapting the technology to other new analytes, fabricating a OBA reader, and undertaking field trials to determine the applicability of this new test system for rapid diagnosis of various natural or induced diseases of military importance.