Zeng Lin, Chen Xi, Zhang Rongrong, Hu Shi, Zhang Hongpeng, Zhang Yi, Yang Hui
Laboratory of Biomedical Microsystems and Nano Devices, Bionic Sensing and Intelligence Center, Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
Marine Engineering College, Dalian Maritime University, Dalian 116026, China.
Micromachines (Basel). 2022 Feb 26;13(3):377. doi: 10.3390/mi13030377.
The separation and purification of a sample of interest is essential for subsequent detection and analysis procedures, but there is a lack of effective separation methods with which to purify nano-sized particles from the sample media. In this paper, a microfluidic system based on negative magnetophoresis is presented for the high-resolution separation of nanoparticles. The system includes on-chip magnetic pole arrays and permalloys that symmetrically distribute on both sides of the separation channel and four permanent magnets that provide strong magnetic fields. The microfluidic system can separate 200 nm particles with a high purity from the mixture (1000 nm and 200 nm particles) due to a magnetic field gradient as high as 10,000 T/m being generated inside the separation channel, which can provide a negative magnetophoretic force of up to 10 pN to the 1000 nm particle. The overall recovery rate of the particles reaches 99%, the recovery rate of 200 nm particles is 84.2%, and the purity reaches 98.2%. Compared with the existing negative magnetophoretic separation methods, our system not only exhibits high resolution on particle sizes (800 nm), but also improves the sample processing throughput, which reaches 2.5 μL/min. The microfluidic system is expected to provide a new solution for the high-purity separation of nanoparticles, as well as nanobiological samples.
对感兴趣的样品进行分离和纯化对于后续的检测和分析程序至关重要，但缺乏从样品介质中纯化纳米级颗粒的有效分离方法。本文提出了一种基于负磁泳的微流控系统，用于纳米颗粒的高分辨率分离。该系统包括芯片上的磁极阵列和坡莫合金，它们对称地分布在分离通道的两侧，以及四个提供强磁场的永久磁铁。由于在分离通道内产生高达10000 T/m的磁场梯度，该微流控系统可以从混合物（1000 nm和200 nm颗粒）中以高纯度分离出200 nm颗粒，这可以为1000 nm颗粒提供高达10 pN的负磁泳力。颗粒的总体回收率达到99%，200 nm颗粒的回收率为84.2%，纯度达到98.2%。与现有的负磁泳分离方法相比，我们的系统不仅在粒径（800 nm）上具有高分辨率，而且提高了样品处理通量，达到2.5 μL/min。该微流控系统有望为纳米颗粒以及纳米生物样品的高纯度分离提供一种新的解决方案。
