Dong Hua, Li Chang-Ming, Zhang Yi-Fan, Cao Xiao-Dong, Gan Ye
Center for Advanced Bionanosystems, School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637457.
Lab Chip. 2007 Dec;7(12):1752-8. doi: 10.1039/b712394a. Epub 2007 Oct 11.
In this paper, a new microfluidic array device has been fabricated with screen printing technology. In contrast to traditional microfabrication processes, our method is simple, inexpensive and also suitable for mass production. The device is used for sandwich-type electrochemical immunoassay, in which probes are covalently attached to the electrode surface via electropolymerized polypyrrole propylic acid (PPA) film. This novel microfluidic system enables the whole array preparation and detection processes, including the probe immobilization, sample injection, enzyme incubation and electrochemical detection, to be conducted in the sealed microchannels. For a demonstration, mouse IgG is selected as the target analyte and its detection is realized by sandwich ELISA with goat anti-mouse IgG, rat anti-mouse IgG (conjugated to alkaline phosphatase) and p-aminophenyl phosphate (PAPP) as the primary antibody, second antibody, and enzyme substrate, respectively. A detection limit of 10 ng mL(-1) (67 pM) is achieved with a dynamic range of 100 ng mL(-1)-10 microg mL(-1). In addition, anti-goat IgG is also immobilized as an alternative probe to test mouse IgG in the solution, in order to demonstrate the multiplexing capability as well as the specificity of the device. As expected, the electrochemical responses are much lower than that using anti-mouse IgG as the probe, indicating good selectivity of the immunoassay device. These results indicate a great promise toward the development of miniaturized, low-cost protein biochips for clinical, forensics, environmental, and pharmaceutical applications.
在本文中，利用丝网印刷技术制造了一种新型微流控阵列装置。与传统的微加工工艺相比，我们的方法简单、成本低且适合大规模生产。该装置用于夹心型电化学免疫分析，其中探针通过电聚合聚吡咯丙酸（PPA）膜共价连接到电极表面。这种新型微流控系统能够在密封的微通道中进行整个阵列的制备和检测过程，包括探针固定、样品注入、酶孵育和电化学检测。作为演示，选择小鼠IgG作为目标分析物，并通过夹心ELISA实现其检测，分别以山羊抗小鼠IgG、大鼠抗小鼠IgG（与碱性磷酸酶偶联）和对氨基苯磷酸（PAPP）作为一抗、二抗和酶底物。检测限达到10 ng mL(-1)（67 pM），动态范围为100 ng mL(-1)-10 μg mL(-1)。此外，还固定了抗山羊IgG作为替代探针来检测溶液中的小鼠IgG，以证明该装置的多重检测能力和特异性。正如预期的那样，电化学响应远低于使用抗小鼠IgG作为探针时的响应，表明免疫分析装置具有良好的选择性。这些结果表明，在开发用于临床、法医、环境和制药应用的小型化、低成本蛋白质生物芯片方面具有巨大潜力。
