A microfluidic ATP-bioluminescence sensor for the detection of airborne microbes

Airborne pathogenic microorganisms are hazardous bioaerosols which often cause serious respiratory diseases. To prevent airborne infectious disease, real-time detection and monitoring systems of airborne pathogens are needed. Since ATP (adenosine triphosphate) is a major biological energy source, the detection of ATP from aerosol reflects the existence of living microbes. Therefore, we developed a new biosensor to detect ATP from aerosols in real-time using an aerosol condensation system, a microfluidic channel, and an ATP-bioluminescence transducer. The condensation system enabled aerosol microbes (4 L) to be hydrosolized (0.2 ml) in 2 min. The bacterial intracellular ATP was then extracted in the passage through the microfluidic channel. The concentration of ATP could be determined by a bioluminescence sensor integrated in the channel. In this study, we used B. subtilis and E. coli JM110 as model airborne microbes. Our system can determine the existence of airborne microbes within 10 min. In the future, the application of our device will extend to the detection of fungi and consequently contribute to improving indoor air quality.