Plastic ELISA-on-a-chip based on sequential cross-flow chromatography
Plastic ELISA-on-a-chip based on sequential cross-flow chromatography
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DOI：
10.1021/ac051453v
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发表时间：
2006-02-01
影响因子：
7.4
通讯作者：
Paek, SH
中科院分区：
文献类型：
--
作者：
Cho, JH;Han, SM;Paek, SH
一种塑料芯片，可以使用酶作为信号发生器进行免疫测定，即，通过将免疫条带并入芯片表面上蚀刻的通道中来开发芯片上ELISA。为了利用错流色谱的分析概念，芯片由水平和垂直方向上的两个错流通道组成。在垂直通道中，我们放置了一个2 mm宽的心肌肌钙蛋白I（cThI）免疫条，除了使用辣根过氧化物酶（HRP）作为示踪剂外，该条与传统的快速检测试剂盒相同。酶底物供应通道和水平流动吸收垫隔室分别横向布置在条带的信号产生垫的每个侧面上。在应用含cTnI的样品时，其通过毛细管作用垂直迁移通过膜条，并发生抗原-抗体结合。15分钟后，通过将HRP的显色底物溶液添加到供应通道中并通过将水平流吸收垫部分叠加到信号产生垫上来引发水平流。在该垫上产生与分析物浓度成比例的颜色信号，5分钟后使用基于数码相机的检测器测量为光密度，并通过归一化后峰下密度的积分来定量。该芯片的检测限为0.1ng/mL，定量限为0.25ng/mL。在测量盲法制备的样品时，芯片性能与参考系统Beckman Coulter Access的性能相关，在检测限的2.5倍差异内。
A plastic chip that can perform immunoassays using an enzyme as signal generator, i.e., ELISA-on-a-chip, was developed by incorporating an immunostrip into channels etched on the surfaces of the chip. To utilize an analytical concept of cross-flow chromatography, the chip consisted of two cross-flow channels in the horizontal and vertical directions. In the vertical channel, we placed a 2-mm-wide immunostrip for cardiac troponin I (cThI), which was identical to a conventional rapid test kit except for the utilization of an enzyme, horseradish peroxidase (HRP), as tracer. An enzyme substrate supply channel and a horizontal flow absorption pad compartment were transversely arranged on each lateral side of the signal generation pad of the strip, respectively. Upon application of a sample containing cTnI, it migrated vertically through the membrane strip by capillary action, and antigen-antibody binding occurred. After 15 min, the horizontal flow was initiated by the addition of a chromogenic substrate solution for HRP into the supply channel and by partial superimposition of the horizontal flow absorption pad onto the signal generation pad. A color signal proportional to the analyte concentration was produced on this pad, measured after 5 min as optical densities using a digital camera-based detector, and quantified by integration of the densities under the peak after normalization. Its calibration curve indicated that the detection limit of the chip was similar to 0.1 ng/mL and its quantification limit was 0.25 ng/mL. In measuring blindly prepared samples, the chip performance correlated with that of a reference system, Beckman Coulter Access, within 2.5-fold discrepancy at the detection limit.