A New Concept for Efficient Sensitivity Amplification of a QCM Based Immunosensor for TNF-α by Using Modified Magnetic Particles under Applied Magnetic Field
A New Concept for Efficient Sensitivity Amplification of a QCM Based Immunosensor for TNF-α by Using Modified Magnetic Particles under Applied Magnetic Field
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DOI：
10.5012/bkcs.2011.32.12.4215
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发表时间：
2011-12-20
影响因子：
1.7
通讯作者：
Go, Jeung Sang
中科院分区：
文献类型：
--
作者：
Bahk, Yeon Kyoung;Kim, Hyung Hoon;Go, Jeung Sang
本研究介绍了一种新的概念，一个简单的，有效的和廉价的灵敏度放大的石英晶体微天平（QCM）为基础的免疫传感器系统检测肿瘤坏死因子-α（TNF-α，TNF）通过使用内置的磁性系统。在磁性颗粒标记的检测抗体（抗人TNF-α）上成功地观察到由于所施加的磁场引起的频率偏移，所述抗体结合到金涂覆的石英晶体上的免疫捕获的TNF-α。在本系统中，频移的幅度取决于磁场的强度和所施加的靶抗原的量。当在施加的磁场下由改性的磁性颗粒产生的额外的内置残余应力时，观察到显著的信号放大。与夹心型非竞争性免疫测定形式结合使用时，计算出的检测下限为25 ngmL（-1），并显示出良好的线性高达2.0 μ gmL（-1）的TNF-α浓度。最重要的是，与仅使用抗原-抗体结合而没有额外的磁放大的相同QCM系统相比，灵敏度提高了4.3倍。
This study introduces a new concept for a simple, efficient and cheap sensitivity amplification of a Quartz Crystal Microbalance (QCM) based immunosensor system for the detection of tumor necrosis factor-alpha (TNF-alpha, TNF) by using an in-built magnetic system. The frequency shift due to the applied magnetic field was successfully observed on magnetic particles labeled detection antibodies, anti-human TNF-alpha, which were bound to the immunologically captured TNF-alpha on the gold coated quartz crystals. In the present system, the magnitude of frequency shift depends on both the strength of magnetic field and the amount of target antigen applied. Significant signal amplification was observed when the additional built-in residual stress generated by the modified magnetic particles under the magnetic field applied. Used in conjunction with a sandwich type non-competitive immunoassay format, the lower detection limit was calculated to be 25 ngmL(-1) and showed good linearity up to TNF-alpha concentrations as high as 2.0 mu gmL(-1). The sensitivity, most importantly, was improved up to 4.3 times compared with the same QCM system which was used only an antigen-antibody binding without additional magnetic amplification.