Micro/Nanophysics Research Laboratory, School of Engineering, RMIT University, Melbourne, Victoria 3001, Australia.
Anal Chem. 2020 Jul 21;92(14):10024-10032. doi: 10.1021/acs.analchem.0c01757. Epub 2020 Jul 6.
Preconcentrating particulate and cellular matter for their isolation or detection is often a necessary and critical sample preparation or purification step in many lab-on-a-chip diagnostic devices. While surface acoustic wave (SAW) microcentrifugation has been demonstrated as a powerful means to drive efficient particle concentration, this has primarily been limited to micron dimension particles. When the particle size is around 1 μm or below, studies on SAW microcentrifugation to date have shown that particle ring-like aggregates can only be obtained in contrast to the localized concentrated clusters that are obtained with larger particles. Considering the importance of submicron particles and bioparticles that are common in many real-world samples, we elucidate why previous studies have not been able to achieve the concentration of these smaller particles to completion, and we present a practical solution involving a novel closed chamber configuration that minimizes sample heating and eliminates evaporation to show that it is indeed possible to drive submicron particle and cell concentration down to 200 nm diameters with SAW microcentrifugation over longer durations.
在许多微流控诊断设备中，为了对颗粒和细胞物质进行分离或检测，通常需要对其进行浓缩，这是一个必要且关键的样品制备或纯化步骤。尽管表面声波（SAW）微离心已被证明是一种有效的颗粒浓缩方法，但这主要限于微米级颗粒。当颗粒尺寸约为 1 μm 或更小时，迄今为止的 SAW 微离心研究表明，与使用较大颗粒获得的局部集中簇相比，只能获得颗粒环状聚集体。考虑到许多实际样本中常见的亚微米颗粒和生物颗粒的重要性，我们阐明了为什么以前的研究未能完全实现这些较小颗粒的浓缩，并提出了一种涉及新颖封闭室配置的实用解决方案，该方案可最大限度地减少样品加热并消除蒸发，以证明通过 SAW 微离心确实可以在较长时间内将亚微米颗粒和细胞浓缩到 200nm 直径。
