Department of Measurement Technology and Industrial Electrical Engineering, Lund University, Sweden.
Lab Chip. 2012 Nov 7;12(21):4296-304. doi: 10.1039/c2lc40697g.
Acoustic trapping of sub-micron particles can allow enrichment and purification of small-sized and low-abundance microorganisms. In this paper, we investigate the dependency of the ability to capture sub-micron particles on the particle concentration. Based on the findings, it is demonstrated that seed particles can be introduced to acoustic trapping, to enable capture of low-abundance sub-micron particles. Without using seed particles, continuous enrichment of 490 nm polystyrene particles is demonstrated in a rectangular capillary with a locally generated acoustic field at high particle concentrations, i.e. above 1% wt. Trapping of sub-micron particles at significantly lower concentrations was subsequently accomplished by seeding 10-12 micrometer-sized particles in the acoustic trap prior to the sub-micron particle capture. Furthermore, the new seeded-particle-aided acoustic trapping technique was employed for the continuous enrichment of bacteria (E. coli) with a capture efficiency of 95%. Finally, seed particle assisted acoustic trapping and enrichment is demonstrated for polymer-based particles down to 110 nm in diameter.
声捕获亚微米颗粒可以实现对小尺寸和低丰度微生物的浓缩和纯化。在本文中，我们研究了捕获亚微米颗粒的能力对颗粒浓度的依赖性。基于这些发现，我们证明了可以向声捕获中引入种子颗粒，从而实现对低丰度亚微米颗粒的捕获。在高颗粒浓度（即高于 1wt%）下，无需使用种子颗粒，即可在局部产生声场的矩形毛细管中连续富集 490nm 聚苯乙烯颗粒。随后，通过在亚微米颗粒捕获之前在声陷阱中引入 10-12 微米大小的颗粒，实现了亚微米颗粒在显著更低浓度下的捕获。此外，我们还采用新的种子颗粒辅助声捕获技术，实现了对细菌（大肠杆菌）的连续富集，捕获效率高达 95%。最后，我们证明了种子颗粒辅助声捕获和浓缩技术可以用于直径低至 110nm 的聚合物基颗粒。
