Tsai H Y, Jian S J, Huang S T, Fuh C Bor
Department of Applied Chemistry, Chung Shan Medical University, Taichung 402, Taiwan.
J Chromatogr A. 2009 Oct 30;1216(44):7493-6. doi: 10.1016/j.chroma.2009.05.029. Epub 2009 May 19.
Functional magnetic nanoparticles are prepared and characterized for protein detection in a magnetic separation channel. This detection method is based on a competitive immunoassay of magnetic separation in thin channels using functional magnetic nanoparticles. We used protein A-IgG complex to demonstrate the feasibility. Free IgG and fixed number of IgG-labeled microparticles were used to compete for limited sites of protein A on the magnetic nanoparticles. Several experimental parameters were investigated for protein detection. The deposited percentages of IgG-labeled microparticles at various concentrations of free IgG were determined and used as a reference plot. The IgG concentration in a sample was deduced and determined based on the reference plot using the deposited percentage of IgG-labeled microparticles from the sample. The linear range of IgG detection was from 5.0 x 10(-8) to 1.0 x 10(-11) M. The detection limit was 3.69 x 10(-12) M. The running time was less than 10 min. Selectivities were higher than 92% and the relative errors were less than 7%. The IgG concentration of serum was determined to be 3.6 mg ml(-1). This measurement differed by 8.3% from the ELISA measurement. The recoveries of IgG spiked in serum were found to be higher than 94%. This method can provide simple, fast, and selective analysis for protein detection and other immunoassay-related applications.
制备了功能性磁性纳米颗粒，并对其在磁分离通道中用于蛋白质检测的性能进行了表征。这种检测方法基于使用功能性磁性纳米颗粒在细通道中进行的磁分离竞争性免疫分析。我们使用蛋白A-IgG复合物来证明其可行性。游离IgG和固定数量的IgG标记微粒用于竞争磁性纳米颗粒上蛋白A的有限位点。研究了几个用于蛋白质检测的实验参数。测定了在不同浓度游离IgG下IgG标记微粒的沉积百分比，并用作参考图。基于参考图，利用样品中IgG标记微粒的沉积百分比推导并确定样品中的IgG浓度。IgG检测的线性范围为5.0×10(-8)至1.0×10(-11)M。检测限为3.69×10(-12)M。运行时间少于10分钟。选择性高于92%，相对误差小于7%。血清中IgG浓度测定为3.6mg/ml(-1)。该测量值与ELISA测量值相差8.3%。血清中加标的IgG回收率高于94%。该方法可为蛋白质检测及其他免疫分析相关应用提供简单、快速且具有选择性的分析。
