title: Classification of chemical and biological warfare agent simulants by surface-enhanced Raman spectroscopy and multivariate statistical techniques.
abstract: Initial results demonstrating the ability to classify surface-enhanced Raman (SERS) spectra of chemical and biological warfare agent simulants are presented. The spectra of two endospores (B. subtilis and B. atrophaeus), two chemical agent simulants (dimethyl methylphosphonate (DMMP) and diethyl methylphosphonate (DEMP)), and two toxin simulants (ovalbumin and horseradish peroxidase) were studied on multiple substrates fabricated from colloidal gold adsorbed onto a silanized quartz surface. The use of principal component analysis (PCA) and hierarchical clustering were used to evaluate the efficacy of identifying potential threat agents from their spectra collected on a single substrate. The use of partial least squares-discriminate analysis (PLS-DA) and soft independent modeling of class analogies (SIMCA) on a compilation of data from separate substrates, fabricated under identical conditions, demonstrates both the feasibility and the limitations of this technique for the identification of known but previously unclassified spectra.
authors.affiliation: Photonics Research Center, Department of Chemistry and Life Science, United States Military Academy, West Point, New York 10996, USA.
authors.forename: William F
authors.initials: WF
authors.lastname: Pearman
authors.forename: Augustus W
authors.initials: AW
authors.lastname: Fountain
mesh_terms: D001694:Biological Warfare / Q000145:classification* / Q000379:methods*; D003627:Data Interpretation, Statistical; D017979:Gold Colloid / Q000737:chemistry; D010316:Particle Size; D011791:Quartz / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D013059:Spectrum Analysis, Raman
chemical_list: D017979:Gold Colloid; D012821:Silanes; D011791:Quartz