College of Food Science and Technology, Shanghai Ocean University , Shanghai 201306, P. R. China.
Division of Engineering in Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School , Cambridge, Massachusetts 02139, United States.
Anal Chem. 2016 Dec 6;88(23):11504-11512. doi: 10.1021/acs.analchem.6b02708. Epub 2016 Nov 16.
The early warning capability of the presence of biological aerosol threats is an urgent demand in ensuing civilian and military safety. Efficient and rapid air sample collection in relevant indoor or outdoor environment is a key step for subsequent analysis of airborne microorganisms. Herein, we report a portable battery-powered sampler that is capable of highly efficient bioaerosol collection. The essential module of the sampler is a polydimethylsiloxane (PDMS) microfluidic chip, which consisted of a 3-loop double-spiral microchannel featuring embedded herringbone and sawtooth wave-shaped structures. Vibrio parahemolyticus (V. parahemolyticus) as a model microorganism, was initially employed to validate the bioaerosol collection performance of the device. Results showed that the sampling efficacy reached as high as >99.9%. The microfluidic sampler showed greatly improved capturing efficiency compared with traditional plate sedimentation methods. The high performance of our device was attributed to the horizontal inertial centrifugal force and the vertical turbulence applied to airflow during sampling. The centrifugation field and turbulence were generated by the specially designed herringbone structures when air circulated in the double-spiral microchannel. The sawtooth wave-shaped microstructure created larger specific surface area for accommodating more aerosols. Furthermore, a mixture of bacterial aerosols formed by V. parahemolyticus, Listeria monocytogenes, and Escherichia coli was extracted by the microfluidic sampler. Subsequent integration with mass spectrometry conveniently identified the multiple bacterial species captured by the sampler. Our developed stand-alone and cable-free sampler shows clear advantages comparing with conventional strategies, including portability, easy-to-use, and low cost, indicating great potential in future field applications.
生物气溶胶威胁物存在的早期预警能力是确保民用和军事安全的迫切需求。在相关的室内或室外环境中高效快速地采集空气样本是后续分析空气中微生物的关键步骤。在此,我们报告了一种便携式电池供电的采样器,该采样器能够高效地采集生物气溶胶。该采样器的基本模块是聚二甲基硅氧烷(PDMS)微流控芯片,由一个 3 圈双螺旋微通道组成,其中嵌入了人字形和锯齿形波状结构。副溶血性弧菌(V. parahemolyticus)作为一种模式微生物,最初被用于验证该设备的生物气溶胶采集性能。结果表明,采样效率高达>99.9%。与传统的平板沉降法相比,该微流控采样器显示出大大提高的捕获效率。我们的设备具有如此优异的性能,归因于采样过程中气流所受到的水平惯性离心力和垂直紊流的共同作用。这种离心力场和紊流是通过在双螺旋微通道中空气循环时特殊设计的人字形结构产生的。锯齿形微观结构为容纳更多的气溶胶创造了更大的比表面积。此外,通过微流控采样器提取了由副溶血性弧菌、单核细胞增生李斯特菌和大肠杆菌组成的细菌气溶胶混合物。随后与质谱仪集成,方便地鉴定出采样器捕获的多种细菌。与传统策略相比,我们开发的独立无绳采样器具有明显的优势,包括便携性、易用性和低成本,这表明它在未来的现场应用中具有巨大的潜力。