TECHNOLOGY DIGEST - Draper Laboratory

Detection of Biological and Chemical Agents Using
Differential Mobility Spectrometry (DMS) Technology
Melissa Krebs, Angela Zapata, Erkinjon Nazarov, Raanan Miller, Isaac Costa, Abraham Sonenshein, Cristina Davis
Copyright © 2005 by The Charles Stark Draper Laboratory, Inc. Printed with permission in IEEE Sensors Journal, Vol. 5, No. 4, August
2005, pp. 696-703
INTRODUCTION
With international concern growing over the potential for chemical and biological terrorism,
there is an urgent need for a sensor that can detect chemical and biological agents quickly and accurately.
Such a sensor must be portable, robust, and sensitive, with fast sample analysis time. We will
demonstrate the use of a micromachined differential mobility spectrometer (DMS) with all these characteristics
that is able to detect multiple agents simultaneously on a time scale of seconds. In this study,
we have demonstrated the ability of the DMS to detect Bacillus subtilis spores, a surrogate for Bacillus
anthracis spores, the causative agent of anthrax. Pyrolysis was used as the sample introduction method
to volatilize the spores before introducing material into the DMS. In addition, we examined the effect
of pyrolysis on B. subtilis spores suspended in sterile water using SDS-PAGE. These experiments
showed that the spores must be heated at 650°C or greater for 5 s or at 550°C for at least 10 s to be
fragmented into particles considerably smaller than 10 kilodaltons (kDa), which the DMS is able to
detect. Several major biomarkers can be distinguished easily above the background of the sterile water
in which the spores are suspended, and we hypothesize that additional biomarkers could be liberated
by further optimizing conditions. The DMS also has shown promise as a detector for chemical weapon
agents, and we have also demonstrated the ability of the DMS to detect nerve and blister agent simulants
at clinically relevant levels.
The use of microbes for bioterrorism is well documented.
As long ago as the Middle Ages, warriors catapulted
bodies of plague victims over the walls of villages under
siege in an attempt to hasten their victory. [1] In the 18 th
century, blankets that had been used by smallpox victims
were intentionally distributed to the Native American
population. [1] Within the last century, there are many
more examples of the use of biological weapons. Japan
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conducted biological warfare experiments in the 1930s
and 1940s, to which outbreaks of plague, cholera, and
typhus were credited. [2] In 1979, there was an epidemic
of inhalation anthrax in Sverdlovsk resulting from a
release of weapons-grade B. anthracis from a military
facility. [3] In 1993, the Aum Shinrikyo cult attempted to
disperse anthrax spores from a high-rise building in
Tokyo. [4] There have also been instances of the intentional