Development of methodology based on commercialized SERS-active substrates for rapid discrimination of Poxviridae virions

Surface-enhanced Raman spectroscopy (SERS) can be made an attractive approach for identification of Raman-active compounds and biological materials (i.e., toxins, viruses, or intact bacterial cells/spores) through development of reproducible, spatially uniform SERS-active substrates. Recently, reproducible (from substrate-to-substrate), spatially homogeneous (over large areas) SERS-active substrates have been commercialized and are now available in the marketplace. We have utilized these patterned surfaces to acquire SERS, spectral signatures of intact bovine papular stomatitis, pseudocowpox, and Yaba monkey tumor viruses. Salient spectral signature features make it possible to discriminate among these genetically distinct Poxviridae-Chordopoxvirinae virions. In addition, partial least-squares, a multivariate calibration method, has been used to develop personal computer-borne algorithms useful for classification of unknown Parapoxvirus (e.g., bovine papular stomatitis virus and pseudocowpox virus) samples based solely on SERS spectral. signatures. To our knowledge, this is the first report detailing application of these commercial-off-the-shelf (COTS) SERS-active substrates to identification of intact poxviruses.