Volume-amplified magnetic bioassay integrated with microfluidic sample handling and high-Tc SQUID magnetic readout
Volume-amplified magnetic bioassay integrated with microfluidic sample handling and high-Tc SQUID magnetic readout
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DOI：
10.1063/1.4999713
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发表时间：
2018-03-01
影响因子：
6
通讯作者：
Winkler, Dag
中科院分区：
文献类型：
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作者：
Sepehri, Sobhan;Eriksson, Emil;Winkler, Dag
提出了一种基于高 T-c 超导量子干涉装置 (SQUID) 的生物测定，在原型微流体平台中读出功能化磁性纳米颗粒 (tMNP)。目标分子识别基于使用挂锁探针连接的体积扩增，然后是滚环扩增 (RCA)。 MNP 用单链寡核苷酸功能化，使 MNP 与大 RCA 线圈产物特异性结合，导致交流磁化率虚部的振幅发生较大变化。使用我们的 SQUID ac 敏感性系统在微流体通道中以 3 μl 的等效样品体积研究来自合成霍乱弧菌靶 DNA 扩增的 RCA 产物。从 SQUID 信号与 RCA 线圈浓度的线性相关性外推，发现我们系统的预计检测限约为 1.0 x 10(5) RCA 线圈（0.2 x 10(-18) mol），相当于 3 μl 样品体积中的 66 fM。这种超高的磁灵敏度以及与微流体样品处理的集成是实现磁性生物测定的关键步骤，以便在护理点快速检测 DNA 和 RNA 靶标。 (C) 2017 年作者。
A bioassay based on a high-T-c superconducting quantum interference device (SQUID) reading out functionalized magnetic nanoparticles (tMNPs) in a prototype microfluidic platform is presented. The target molecule recognition is based on volume amplification using padlock-probe-ligation followed by rolling circle amplification (RCA). The MNPs are fiinctionalized with single-stranded oligonucleotides, which give a specific binding of the MNPs to the large RCA coil product, resulting in a large change in the amplitude of the imaginary part of the ac magnetic susceptibility. The RCA products from amplification of synthetic Vibrio cholera target DNA were investigated using our SQUID ac susceptibility system in microfluidic channel with an equivalent sample volume of 3 mu l. From extrapolation of the linear dependence of the SQUID signal versus concentration of the RCA coils, it is found that the projected limit of detection for our system is about 1.0 x 10(5) RCA coils (0.2 x 10(-18) mol), which is equivalent to 66 fM in the 3 mu l sample volume. This ultra-high magnetic sensitivity and integration with microfluidic sample handling are critical steps towards magnetic bioassays for rapid detection of DNA and RNA targets at the point of care. (C) 2017 Author(s).