AVS 50th International Symposium
    Homeland Security Topical Conference Wednesday Sessions
       Session HS-WeP

Paper HS-WeP7
A Rapid Optical Assay for the Detection of Bioterriorism Agents Using Thin-Film Technology

Wednesday, November 5, 2003, 11:00 am, Room Hall A-C

Session: Poster Session on Science & Technology for Homeland Security
Presenter: S.C. Francesconi, Nova Research, Inc.
Authors: S.C. Francesconi, Nova Research, Inc.
A.M. Churilla, Naval Research Laboratory
Correspondent: Click to Email
Rapid, field analysis of environmental samples for the presence of biological agents is important in both military and civilian law enforcement and public health applications. Development of assay formats, useful in these settings must be easy to operate and interpret. Additionally, the assay must be highly sensitive yet yield a low rate of false positive results. To this end, we have modified a commercially available, thin-film format to develop an assay capable of detecting multiple biological agents, simultaneously. The current assay is capable of simultaneously detecting ricin, botulinum toxin and anthrax, plus negative and positive controls, simultaneously in less than 30 minutes. The assay is performed on disposable silicon nitride wafers spotted with capture antibody specific to target agents. Samples, mixed with enzyme-coupled detector antibody are exposed to the capture antibody-spotted wafers. Exposure of the wafer to enzyme substrate results in a thin-film. Final detection of agents, therefore, is creation of a change in refractive properties of the wafer spots yielding a visible color change proportional to the amount of antigen originally present in the sample. The assays perform well using a number of sample matrixes including tap water, sea water or oily water. Further, the assay can be expanded to include additional target agent detection capability.