title: Bioaerosol detection and characterization by surface-enhanced Raman spectroscopy.
abstract: Instrumentation has been developed to detect and characterize airborne pollen and bacteria rapidly by injecting a bioaerosol into a nanocolloidal suspension of silver particles using a micropump. The biological particles were mixed with the silver colloid in order to deposit the metallic particles on the surface of the bioanalyte. The silver/bioanalyte suspension was pumped through a light scattering cuvette, and the enhanced Raman spectrum was recorded. Surface-enhanced Raman spectra are presented for tree pollen (cottonwood and redwood pollen) and a bacterium (Escherichia coli), and the E. coli spectra are compared with results obtained from the literature and with results obtained previously by mixing various concentrations of the bioanalyte with the silver colloid. Although the system has not been optimized to maximize the Raman spectra, it is shown spectra can be obtained rapidly. Some assignments of the chemical bonds associated with the spectra are based on previously published results for bacteria and pollen.
authors.affiliation: Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195-1700, USA.
authors.forename: Atanu
authors.initials: A
authors.lastname: Sengupta
authors.forename: Navpreet
authors.initials: N
authors.lastname: Brar
authors.forename: E James
authors.initials: EJ
authors.lastname: Davis
mesh_terms: D000336:Aerosols / Q000032:analysis; D003102:Colloids / Q000737:chemistry; D004926:Escherichia coli / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D011058:Pollen / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D000336:Aerosols; D003102:Colloids; D012834:Silver