In situ lysis droplet supply to efficiently extract ATP from dust particles for near-real-time bioaerosol monitoring

Abstract

Simultaneous improvement in detection speed and reliability is critical for bioaerosol monitoring. Recent rapid detection strategies exhibit difficulties with misinterpretation due to signal interference from co-existing nonbiological particles, whereas biomolecular and bioluminescent approaches require long process times (>several tens of minutes) to generate readable values despite their better detection reliability. To overcome these shortcomings, we designed a system to achieve rapid reliable field detection of bioaerosols (>104 relative luminescence units [RLU] per cubic meter of air) in <3 min processing time (equivalent to 24 L sampling air volume) by employing a lysis droplet supply for efficient extraction of adenosine triphosphate (ATP) from particulate matter (PM) and a photomultiplier tube detector for signal amplification of ATP bioluminescence. We also suggested the use of the ratio of RLU (m-3) to total PM (μg m-3), or specific bioluminescence (RLU μg-1), as a measure of the biofraction of PM (i.e., potential biohazards). A correlation between RLU and colony forming unit was also obtained from simultaneous aerosol sampling using an agar-inserted sampler.