An integrated bioaerosol sampler with simultaneous sampling and droplet encapsulation for the monitoring of airborne bacteria

Abstract

Monitoring of bioaerosols requires the provision of highly concentrated liquid samples in a short period. Such a bioaerosol sampler should not only be a low-cost, compact device but should also have a technology to achieve a high collection efficiency and concentrated samples in small liquid volumes. In this study, for the first time, we developed a bioaerosol sampler that can simultaneously collect bacteria and highly concentrated liquid samples by combining electrostatic and electrowetting technologies. The sampler consists of two parts-a miniature corona discharger and a bacteria collection and liquid sample conversion section. The device can be fabricated using three-dimensional printing, liquid metal, and printed circuit boards. The newly developed sampler collects bacteria and produces highly concentrated liquid samples of tens of microliters, using electrostatic and electrowetting techniques, on an integrated single chip. A one-to-one comparative evaluation was performed between the developed sampler and a reference sampler, which showed that the developed sampler was able to provide a higher concentration of bacterial liquid samples in a shorter time than the reference sampler. Additionally, the developed sampler enabled detection in low-concentration bacterial environments, which was not achieved with reference samplers. The developed sampler is expected to represent a cornerstone in the monitoring of bioaerosols.