Xu Hui, Mao Xun, Zeng Qingxiang, Wang Shengfu, Kawde Abdel-Nasser, Liu Guodong
College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, P. R. China.
Anal Chem. 2009 Jan 15;81(2):669-75. doi: 10.1021/ac8020592.
The highly specific molecular recognition properties of aptamers are combined with the unique optical properties of gold nanoparticles for the development of a dry-reagent strip biosensor that enables qualitative (visual)/quantitative detection of protein within minutes. A model system comprising thrombin as an analyte and a pair of aptamer probes is used to demonstrate the proof-of-concept on the conventional lateral flow test strip. The assay avoids the multiple incubation and washing steps performed in most current aptamer-based protein analyses. Although qualitative tests are realized by observing the color change of the test zone, quantitative data are obtained by recording the optical responses of the test zone with a portable "strip reader". The response of the biosensor is linear over the range of 5-100 nM of thrombin with a detection limit of 2.5 nM (S/N = 3). By comparing the analytical performances of the aptamer-based strip biosensor with the antibody-based strip sensor, we can demonstrate that aptamers are equivalent or superior to antibodies in terms of specificity and sensitivity, respectively. The sensor was used successfully for detection of thrombin in human plasma samples. It shows great promise for use of aptamer-functionalized gold nanoparticle probes in dry-reagent strip biosensors for point-of-care or in-field detection of proteins.
适体的高度特异性分子识别特性与金纳米颗粒独特的光学特性相结合，用于开发一种干式试剂条生物传感器，该传感器能够在数分钟内实现对蛋白质的定性（视觉）/定量检测。使用包含凝血酶作为分析物和一对适体探针的模型系统，在传统的侧向流动测试条上证明了概念验证。该检测方法避免了目前大多数基于适体的蛋白质分析中进行的多次孵育和洗涤步骤。虽然通过观察测试区的颜色变化实现定性测试，但通过使用便携式“试纸读取器”记录测试区的光学响应来获得定量数据。生物传感器的响应在凝血酶浓度为5-100 nM范围内呈线性，检测限为2.5 nM（信噪比=3）。通过比较基于适体的试纸生物传感器与基于抗体的试纸传感器的分析性能，我们可以证明适体在特异性和灵敏度方面分别等同于或优于抗体。该传感器已成功用于检测人血浆样品中的凝血酶。它显示出在干式试剂条生物传感器中使用适体功能化金纳米颗粒探针对蛋白质进行即时检测或现场检测的巨大前景。
