Miniature Sensors for Biological Warfare Agents using Fatty Acid ...

1.3. Pyrolysis for the Identification of Biologicals
There exists a large range of organisms and constituents that have been
differentiated using pyrolysis methods. These methods are introduced briefly
based upon the target biological category: bacterial, viral, or sporulated (bacterial).
This introduction is meant to serve as an illustration of the potential markets or
applications for the miniature sensor system developed in this LDRD.
1.3.1. Bacterial
Differentiation of several gram-positive and gram-negative organisms based upon
gram-type was achieved using pyrolysis/methylation/MS [25]. The organisms,
including five Bacillus strains, 2 Staphylococcus strains, and 5 Pseudomonas
strains, and the differentiation was based upon FAMEs between C12 and C19
without chromatography. Table 3 summarizes comparative results for B. cereus
and B. fluorescens, showing a clear difference in signatures for the two bacteria;
B. cereus is type gram positive and B. fluorescens is type gram negative. Full
proof-of- concept development will consider signatures of the most common BW
agents, their simulants, and less toxic bacteria as test platform samples, as well as
background and interferant signals.
Table 3: Relative amounts of fatty acid constituents, detected by pyrolysis/mass
spectrometry[26].
Fatty Acid
% by MS Analysis
Pseudomonas fluorescens Bacillus cereus
C12:0 10.33 0.44
C13:0 0.09 11.2
C15:0 0.16 39.0
C16:0 28.8 3.2
C16:1 22.25 9.0
C17:0 17.7 7.0
C17:1 0.1 10.7
C18:1 9.0 not detected
Error! Not a valid bookmark self-reference. summarizes some of the fatty acids
detected using pyrolysis methods for other BW agents and simulants.
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