Separation, Sensing, and Metagenomic Analysis of Aerosol Particles Using MMD Sensors

In this study, we developed a new metal mesh device (MMD) sensor to quantify the amount of aerosol particles. MMDs are substrate materials consisting of thin membranes with a periodic structure on smooth surfaces that can be used to detect and separate particles. The surface structure comprises square apertures of characteristic size that bestow unique optical properties. Aerosol particles, including the damaging environmental pollutant particulate matter 2.5 (PM2.5), were separated based on size and captured on MMD surfaces using a small air pump. The amount of captured particles was evaluated by band shifts in infrared (IR) transmittance spectra. Furthermore, bacterial genomic DNA attached to aerosol particles could be extracted with high yield, and extracted DNA resulted in bacterial constitution, as demonstrated by next-generation sequencing (NGS) analysis of bacterial 16S ribosomal DNA. MMD sensors were used to analyze aerosol particles from suburbs of Kenya and Japan. The results provided information on the bacterial biota of the environment in each local area, and pathogenic bacteria were identified. The results suggest that MMD sensors are useful tools for epidemiological and environmental studies, as well as quality control applications for drugs, fine chemicals, and food components.