Disposable electrochemical immunosensor diagnosis device based on nanoparticle probe and immunochromatographic strip
Disposable electrochemical immunosensor diagnosis device based on nanoparticle probe and immunochromatographic strip
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DOI：
10.1021/ac070691i
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发表时间：
2007-10-15
影响因子：
7.4
通讯作者：
Lin, Yuehe
中科院分区：
文献类型：
--
作者：
Liu, Guodong;Lin, Ying-Ying;Lin, Yuehe
我们描述了一种一次性电化学免疫传感器诊断装置，该装置将免疫层析条技术与电化学免疫分析相结合，并利用量子点（QD，CdS@ZnS）作为放大信号输出的标记物。该装置利用了传统免疫层析试纸条测试的速度和低成本以及基于纳米颗粒的电化学免疫分析的高灵敏度。在免疫层析条上进行夹心免疫反应，并通过用一次性丝网印刷电极对溶解的金属组分（镉）进行高灵敏度溶出伏安测量来确定测试区中捕获的QD标记，所述电极嵌入测试区上的膜下方。新设备与便携式电化学分析仪相结合，显示出对疾病相关蛋白质生物标志物的现场和即时定量检测的巨大潜力。参数（例如，QD标记的伏安测量、抗体固定、QD-抗体的加载量和免疫反应时间），这些因素决定了装置的灵敏度和再现性。优化后的装置的伏安响应在0.1-10 ng/mL IgG范围内呈高度线性，检测限估计为30 pg/mL，免疫反应时间为7 min。使用20分钟的免疫反应时间，检测限提高到10 pg/mL（-1）。该装置已成功地应用于检测前列腺特异性抗原（PSA）在人血清样品中的检测限为20 pg mL（-1）。结果与市售PSA酶联免疫吸附测定试剂盒进行了验证，结果具有较高的一致性。因此，新的一次性电化学诊断装置为蛋白质生物标志物检测提供了快速、临床准确和定量的工具。
We describe a disposable electrochemical immunosensor diagnosis device that integrates the inummochromatographic strip technique with an electrochemical immunoassay and exploits quantum dot (QD, CdS@ZnS) as labels for amplifying signal output. The device takes advantage of the speed and low cost of the conventional inummochromatographic strip test and the high sensitivity of the nanoparticle-based electrochemical immunoassay. A sandwich immunoreaction was performed on the immunochromatographic strip, and the captured QD labels in the test zone were determined by highly sensitive stripping voltammetric measurement of the dissolved metallic component (cadmium) with a disposable screen-printed electrode, which is embedded underneath the membrane on the test zone. The new device coupled with a portable electrochemical analyzer shows great promise for in-field and point-of-care quantitative testing of disease-related protein biomarkers. The parameters (e.g., voltammetric measurement of QD labels, antibody immobilization, the loading amount of QD-antibody, and the immunoreaction time) that govern the sensitivity and reproducibility of the device were optimized with IgG model analyte. The voltammetric response of the optimized device is highly linear over the range of 0.1-10 ng mL(-1) IgG, and the limit of detection is estimated to be 30 pg mL(-1) in association with a 7-min immunoreaction time. The detection limit was improved to 10 pg mL(-1) using a 20-min immunoreaction time. The device has been successfully applied for the detection of prostate-specific antigen (PSA) in human serum sample with a detection limit of 20 pg mL(-1). The results were validated by using the commercial PSA enzyme-linked immunosorbent assay kit and showed high consistency. The new disposable electrochemical diagnosis device thus provides a rapid, clinically accurate, and quantitative tool for protein biomarker detection.