18 January 1999 Monitoring biological aerosols using UV fluorescence
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Proceedings Volume 3533, Air Monitoring and Detection of Chemical and Biological Agents; (1999) https://doi.org/10.1117/12.336868
Event: Photonics East (ISAM, VVDC, IEMB), 1998, Boston, MA, United States
Abstract
An apparatus has been designed and constructed to continuously monitor the number density, size, and fluorescent emission of ambient aerosol particles. The application of fluorescence to biological particles suspended in the atmosphere requires laser excitation in the UV spectral region. In this study, a Nd:YAG laser is quadrupled to provide a 266 nm wavelength to excite emission from single micrometer-sized particles in air. Fluorescent emission is used to continuously identify aerosol particles of biological origin. For calibration, biological samples of Bacillus subtilis spores and vegetative cells, Esherichia coli, Bacillus thuringiensis and Erwinia herbicola vegetative cells were prepared as suspensions in water and nebulized to produce aerosols. Detection of single aerosol particles, provides elastic scattering response as well as fluorescent emission in two spectral bands simultaneously. Our efforts have focuses on empirical characterization of the emission and scattering characteristics of various bacterial samples to determine the feasibility of optical discrimination between different cell types. Preliminary spectroscopic evidence suggest that different samples can be distinguished as separate bio-aerosol groups. In addition to controlled sample results, we will also discuss the most recent result on the effectiveness of detection outdoor releases and variations in environmental backgrounds.
© (1999) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Jay D. Eversole, Dominick Roselle, Mark E. Seaver, "Monitoring biological aerosols using UV fluorescence", Proc. SPIE 3533, Air Monitoring and Detection of Chemical and Biological Agents, (18 January 1999); doi: 10.1117/12.336868; https://doi.org/10.1117/12.336868
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