Detection of magnetic nanoparticles with ac susceptibility measurement
Detection of magnetic nanoparticles with ac susceptibility measurement
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DOI：
10.1016/j.physc.2004.01.146
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发表时间：
2004-10-01
影响因子：
1.7
通讯作者：
Enpuku, K
中科院分区：
文献类型：
--
作者：
Yang, TQ;Abe, M;Enpuku, K
我们利用交流磁化率测量方法开发了磁性纳米颗粒的检测系统。在该方法中，将激励场施加到粒子，并且用拾取线圈检测来自粒子的所得信号场。激励场到拾波线圈的耦合可以减小到1/10（6）。当使用半径为2.2 mm且匝数为100的室温铜拾取线圈时，我们检测到重量低至7 ng的Fe 3 O 4颗粒。该值受到来自基底的噪声的限制，尽管我们可以期望从系统的固有噪声中检测到0.8ng的重量。研究还表明，采用高温超导量子干涉仪（SQUID）耦合冷却拾波线圈可以大大改善系统的本征噪声。(C)2004 Elsevier B. V.保留所有权利。
We developed a detection system for the magnetic nanoparticles utilizing an ac susceptibility measurement method. In this method, an excitation field is applied to the particles, and the resulting signal field from the particles is detected with a pickup coil. The coupling of the excitation field to the pickup coil can be reduced to 1/10(6). When a room temperature copper pickup coil with radius of 2.2 mm and the number of turns of 100 was used, we detected Fe3O4 particles down to the weight of 7 ng. This value was limited by the noise from a substrate although we can expect to detect the weight of 0.8 ng from the intrinsic noise of the system. It was also shown that the intrinsic noise of the system can be much improved by using a cooled pickup coil coupled to a high-T-c superconducting quantum interference device (SQUID). (C) 2004 Elsevier B.V. All rights reserved.