Magnetic measurements of suspended functionalised ferromagnetic beads under DC applied fields
Magnetic measurements of suspended functionalised ferromagnetic beads under DC applied fields
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DOI：
10.1016/j.jmmm.2009.01.019
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发表时间：
2009-07-01
影响因子：
2.7
通讯作者：
Lees, Martin
中科院分区：
文献类型：
--
作者：
De Los Santos, Luis V.;Llandro, Justin;Lees, Martin
本文介绍了一种在液体悬浮液中获得磁珠（Spherotech Inc.）磁滞回线的简单方法。磁测量在直流磁特性测量系统（MPMS-SQUID传感器）中进行。样品以铁磁珠（表面功能化NH2，平均直径4.32 μ m）为基础，在干燥、悬浮于蔗糖溶液和荧光基团功能化后悬浮三种条件下制备。用非磁性塑料制成的特殊小容器（长1.3厘米）被设计用来将珠子放在液体中。结果表明，在所有情况下，磁珠的残余磁化强度均为最大外加磁场强度的一半。然而，由于额外的旋转自由度，悬浮在液体中的珠子不呈现矫顽力。本文还讨论了铁磁珠和不同结构的磁性元件在生物检测中的应用。爱思唯尔B.V.版权所有
In this work, a simple technique to obtain the hysteresis loops of magnetic beads (Spherotech Inc.) in liquid suspension is presented. The magnetic measurements were taken in a DC Magnetic Property Measurement System (MPMS-SQUID sensor). Samples were based on ferromagnetic beads (surface-functionalized NH2, mean diameter 4.32 mu m) prepared in three conditions: dry, suspended in sucrose solution and in suspension after functionalization with fluorophore. Special small containers (1.3 cm long) made of non magnetic plastic were designed to hold the beads in liquid. The results indicate that the bead's remnant magnetization is half of the value at maximum applied field in all cases. However, due to the additional degrees of rotational freedom, beads suspended in a liquid do not present coercivity. The use of ferromagnetic beads and magnetic elements of different architectures for applications in bioassays is also discussed. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.