Construction of DNA sandwich electrochemical biosensor with nanoPbS and nanoAu tags on magnetic microbeads
Construction of DNA sandwich electrochemical biosensor with nanoPbS and nanoAu tags on magnetic microbeads
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DOI：
10.1016/j.bios.2009.04.012
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发表时间：
2009-07-15
影响因子：
12.6
通讯作者：
Cao, Wei
中科院分区：
文献类型：
--
作者：
Du, Ping;Li, Hongxia;Cao, Wei
基于磁性微球和生物条形码修饰的Au纳米粒子（NPs）及PbS纳米粒子的复合扩增，构建了一种新型的夹心式电化学生物传感器。在该方法中，磁性微球被4层聚电解质包覆，以增加磁性微球表面的羧基，从而提高捕获DNA的量。磁性微球表面的氨基功能化捕获DNA与靶DNA的一端杂交，靶DNA的另一端与末端标记有Au NPs的信号DNA探针杂交。用生物条形码修饰Au NPs，并将PbS NPs用作鉴定靶寡核苷酸的标记物。磁性微球的修饰可以使更多的氨基末端捕获DNA，生物条形码可以增加与靶DNA结合的Au NPs的量。阳极溶出伏安法（ASV）检测铅离子进一步提高了传感器的灵敏度。结果表明，该DNA生物传感器具有良好的选择性和灵敏度。在最佳条件下，该方法的线性范围为2.0 × 10 ~（-14）M ~ 1.0 × 10 ~（-12）M，检出限为5.0 × 10 ~（-15）M。(C)2009爱思唯尔有限公司版权所有。
A novel and sensitive sandwich electrochemical biosensor based on the amplification of magnetic microbeads and Au nanoparticles (NPs) modified with bio bar code and PbS nanciparticles was constructed in the present work. In this method, the magnetic microspheres were coated with 4 layers polyelectrolytes in order to increase carboxyl groups on the surface of the magnetic microbeads, which enhanced the amount of the capture DNA. The amino-functionalized capture DNA on the surface of magnetic microbeads hybridized with one end of target DNA, the other end of which was hybridized with signal DNA probe labelled with Au NPs on the terminus. The Au NPs were modified with bio bar code and the PbS NPs were used as a marker for identifying the target oligoncleotide. The modification of magnetic microbeads could immobilize more amino-group terminal capture DNA, and the bio bar code could increase the amount of Au NPs that combined with the target DNA. The detection of lead ions performed by anodic stripping voltammetry (ASV) technology further improved the sensitivity of the biosensor. As a result, the present DNA biosensor showed good selectivity and sensitivity by the combined amplification. Under the optimum conditions, the linear relationship with the concentration of the target DNA was ranging from 2.0 x 10(-14) M to 1.0 x 10(-12) M and a detection limit as low as 5.0 x 10(-15) M Was obtained. (C) 2009 Elsevier B.V. All rights reserved.