Department of Microtechnology and Nanoscience-MC2, Chalmers University of Technology, SE-412 96, Göteborg, Sweden.
Lab Chip. 2009 Dec 7;9(23):3433-6. doi: 10.1039/b912646e. Epub 2009 Oct 1.
We demonstrate ElectroWetting-On-Dielectric (EWOD) transport and SQUID gradiometer detection of magnetic nanoparticles (MNPs) suspended in a 2 microl de-ionized water droplet. This proof-of-concept methodology constitutes the first development step towards a highly sensitive magnetic immunoassay platform with SQUID readout and droplet-based sample handling. Magnetic AC-susceptibility measurements were performed on MNPs with a hydrodynamic diameter of 100 nm using a high-Tc dc Superconducting Quantum Interference Device (SQUID) gradiometer as detector. We observed that the signal amplitude per unit volume is 2.5 times higher for a 2 microl sample droplet compared to a 30 microl sample volume.
我们展示了基于电润湿的（EWOD）传输和超导量子干涉仪（SQUID）梯度仪对悬浮在 2 微升去离子水中的磁性纳米粒子（MNPs）的检测。这种概念验证方法是朝着具有 SQUID 读出和基于液滴的样品处理的高灵敏度磁性免疫分析平台迈出的第一步。使用高 Tc 直流超导量子干涉仪（SQUID）梯度仪作为探测器，对直径为 100nm 的 MNPs 进行了磁交流磁化率测量。我们观察到，与 30 微升样品体积相比，2 微升样品液滴的单位体积信号幅度高 2.5 倍。
