Low Tc SQUID measurement system for magnetic relaxation immunoassays in unshielded environment
Low Tc SQUID measurement system for magnetic relaxation immunoassays in unshielded environment
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DOI：
10.1109/77.919606
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发表时间：
2001-03-01
影响因子：
1.8
通讯作者：
Trahms, L
中科院分区：
文献类型：
--
作者：
Haller, A;Matz, H;Trahms, L
最近，一种基于SQUID测量系统的新技术被证明用于检测免疫化学反应。反应伙伴被磁性纳米颗粒标记，经过免疫化学反应后，由于迁移率的降低，它们的磁弛豫行为发生了变化。我们已经开发了一个专门用于在非屏蔽环境中运行的磁弛豫免疫分析(MARAS)的SQUID系统。该系统由6个SQUID磁力仪电子组合成一个二阶梯度仪组成。梯度计由FLL输出信号电减或三SQUID梯度计方法构成。通过评估弛豫信号的幅度(平均4个磁化周期)，检测到了与600pmolFe相对应的最小数量的(选定的)Fe2O3-颗粒，证明了该测量系统用于生化实验室诊断的潜力。
A novel technique for detecting immunochemical reactions based on a SQUID measurement system has recently been demonstrated. The reaction partners are labeled by magnetic nanoparticles which, after an immunochemical reaction, display changes of their magnetic relaxation behaviour due to a reduction of their mobility. We have developed a SQUID system dedicated to magnetic relaxation immunoassays (MARIAs) operating in unshielded environment. The system consists of 6 SQUID magnetometers electronically combined to a second-order gradiometer. The gradiometer is formed by electronic subtraction of FLL output signals or by the Three SQUID Gradiometer approach. By evaluating the amplitude of relaxation signals (average of 4 magnetization cycles) a minimum amount of (selected) Fe2O3-particles corresponding to 600 pmol Fe was detected demonstrating the potential of the measurement system for biochemical laboratory diagnostics.