Autonomous Pathogen Detection Systems for use with Biological Terrorism Defense

Stu Dent

Chemistry 345 Junior Seminar

Biological terrorism is a major threat to the United States as well as the rest of the world.  People are especially vulnerable when the agents are in aerosol form as it is difficult to detect.  While aerosol detection systems are present throughout the United States, these systems do not give immediate results and are expensive to operate.  An alternative to aerosol detection systems is the autonomous pathogen detection system (APDS).  APSD continually monitors air conditions and collects samples.  The fully automated system also analyzes results and determines what type of response is required for each scenario.  Bacillus anthracis, Yersinia pestis, Bacillus globigii, and botulinum toxoid were the pathogens that were tested for different levels of concentration.  These pathogens were put in aerosol form and allowed to enter a test chamber with the APSD.  The autonomous pathogen detection system identified all of the agents as well as negative controls.  The APDS also determined the amount of pathogen that was released into the air.  This completely autonomous system showed a very low false positive rate.

Bibliography

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A Computational Investigation of the Reactions of Methylene, Chlorocarbene, and Dichlorocarbene with Cyclopropane

 Stu Dent, Chemistry Junior Seminar, CHEM 345

 Experimental data shows that the reaction of a carbene with cyclopropane primarily yields the product of C-H insertion — methyl-cyclopropane.  Computational studies were run to investigate why this pathway is taken as opposed to a C-C insertion leading to a less strained product – cyclobutane. Three different carbenes were used, so that the effect of carbene stability on the reaction pathway could be observed.  These investigations confirmed the experimental results, with the major product being C-H insertion, and potential energy surfaces for the experimental pathways were constructed. However, with both chlorocarbene and dichlorocarbene cleavage of the ring was observed instead of a normal C-C insertion. Yet in these cases the activation energy barriers are high enough that dimerization of the carbene is more likely than either of the insertions.

(1) Sevin, F., McKee, M.L., Shevlin, P.B. J. Org. Chem. 2004, 69, 382-386