The Impact of Environmental Aging Processing on Bioaerosol Detection Using Circular Intensity Differential Scattering (CIDS)

DANIEL N. ACKERMAN, Yong-Le Pan, Kevin K. Crown, Ashley R. Ravnholdt, Elizabeth A. Klug, Joshua L. Santarpia, National Strategic Research Institute

     Abstract Number: 221
     Working Group: Aerosol Science of Infectious Diseases: Lessons and Open Questions on Models, Transmission and Mitigation

Abstract
Circular intensity differential scattering (CIDS) has recently been used to discriminate biological from non-biological particles in an aerosol based direct detection of nucleic acids in a single particle. Most sensors that can discriminate biological from non-biological are based on laser-induced fluorescence (LIF). Despite their continued use, recent studies have shown that LIF detection signatures are unstable under atmospheric conditions, complicating the interpretation of LIF sensor data. Since CIDS signals are based on the chirality of nucleic acids, environmental damage to nucleic acid is not likely to impact the CIDS return in the same way that it impacts the LIF signal. In order to test this hypothesis, MS2 aerosol particles were generated and exposed to both simulated sunlight and ozone in the Biological Aerosol Reaction Chamber (Bio-ARC). These rapidly aged particles will then be measured by a Wideband Integrated Bioaerosol Sensor (WIBS-4a), which measures aerosol fluorescence excited at 280 and 370 nm, and a novel aerosol measurement system that relies on CIDS. The impact of this simulated aging on both LIF returns and the CIDS returns will be evaluated. Since LIF and CIDS returns are likely to be impacted differently by environmental aging processes, this data will help inform the potential future uses of CIDS in the bioaerosol measurement applications.