AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Using Real-time Multiband Fluorescence Signatures to Discriminate between Bioaerosol Classes
Darrel Baumgardner, Kevin McCabe, Greg Kok, Gary Granger, MARK T. HERNANDEZ, University of Colorado Boulder
Abstract Number: 442 Working Group: Portable and Inexpensive Sensor Technology for Air Quality Monitoring
Abstract Ultraviolet laser induced fluorescence (UV-LIF) is gaining increased attention for its ability to rapidly identify large numbers of airborne particles, which contain materials of primary biological origin. While a new generation of commercial UV-LIF instruments has demonstrated the utility of particle fluorescence in a multitude of field trials, the resolution of these instruments in discriminating between different classes of aerobiological particles remains to be catalogued.
We report here the characteristic responses of a Waveband Integrated Bioaerosol Sensor (WIBS-4) to recognize bioaerosols which serve as model aerobiological classes germane to public health. A research grade WIBS instrument was challenged in environmentally controlled chamber with pure cultures of airborne vegetative bacteria, bacterial spores, fungal spores and pollen grains. Following calibrations, the instrument was used to continuously monitor airborne particle loads under both dry and humid conditions containing the following (pure culture) bioaerosols: vegetative Gram positive bacteria of Bacillus subtilis, aerosolized at various stages of their growth cycle, (azide) inactivated cells, and nascent bacterial spores. The more common fungal spores, including but not limited to Aspergillus, Alternaria, Penicillium, Chaetomium, and Cladosporium spp., as well as more than 15 species of temperate pollen grains were included in these aerosol challenges: Acer, Alnus, Ambrosia, Artemesia, Betula, Carya, Eucalyptus, Fragus, Juglands, Juniperous, Morus and Phelum spp.
Distinct fluorescent signatures emerged which corresponded to phenotypic groupings as challenged in the following channels: emission between 310–400 nm, and 420–650 nm wavebands following 280 nm excitation; and, subsequent emission in a 420–650 nm waveband following 370 nm excitation. As judged by relative intensity, the ratio of 280/370 excitation response in the 420-650 nm bandwidth is a sensitive metric which can be used to resolve fungal spores from pollen. These results suggest that with an expanded library, multi-channel LIF offers a reliable platform for phenotypic bioaerosol discrimination.