The force acting on a superparamagnetic bead due to an applied magnetic field
The force acting on a superparamagnetic bead due to an applied magnetic field
复制标题
DOI：
10.1039/b705045c
复制
发表时间：
2007-01-01
期刊：
影响因子：
6.1
通讯作者：
Whitesides, George M.
中科院分区：
文献类型：
--
作者：
Shevkoplyas, Sergey S.;Siegel, Adam C.;Whitesides, George M.
本文描述了在电流通过共面金属丝产生的弱磁场的影响下，超顺磁珠在微流控通道中的运动模型。基于超顺磁珠(悬浮在生物相关介质中)所受磁力的传统表达式和制造商提供的参数的模型与实验数据不匹配。为了将数据拟合到模型中，有必要对传统的力的表达式进行修改，以考虑珠子的非零初始磁化强度，并使用珠子的初始磁化强度和磁化率作为可调参数。磁化率的最佳拟合值与制造商提供的值有很大偏差，但与使用实验中使用的同一瓶中的珠子独立测量的磁化曲线计算的值非常一致。这项研究的结果将有助于需要准确预测超顺磁珠在弱磁场影响下在水悬浮液中的行为的研究人员。磁场对磁珠的作用力的推导也确定了用于这种相互作用的正确处理方法，并解决了整个文献中存在的差异。
This paper describes a model of the motion of superparamagnetic beads in a microfluidic channel under the influence of a weak magnetic field produced by an electric current passing through a coplanar metal wire. The model based on the conventional expression for the magnetic force experienced by a superparamagnetic bead ( suspended in a biologically relevant medium) and the parameters provided by the manufacturer failed to match the experimental data. To fit the data to the model, it was necessary to modify the conventional expression for the force to account for the non-zero initial magnetization of the beads, and to use the initial magnetization and the magnetic susceptibility of the beads as adjustable parameters. The best-fit value of susceptibility deviated significantly from the value provided by the manufacturer, but was in good agreement with the value computed using the magnetization curves measured independently for the beads from the same vial as those used in the experiment. The results of this study will be useful to researchers who need an accurate prediction of the behavior of superparamagnetic beads in aqueous suspensions under the influence of weak magnetic fields. The derivation of the force on a magnetic bead due to a magnetic field also identifies the correct treatment to use for this interaction, and resolves discrepancies present throughout the literature.