Li Xiang, Scida Karen, Crooks Richard M
Department of Chemistry, The University of Texas at Austin , 105 East 24th Street, Stop A5300, Austin, Texas 78712-1224, United States.
Anal Chem. 2015 Sep 1;87(17):9009-15. doi: 10.1021/acs.analchem.5b02210. Epub 2015 Aug 10.
Here we show that a simple paper-based electrochemical sensor, fabricated by paper folding, is able to detect a 30-base nucleotide sequence characteristic of DNA from the hepatitis B virus (HBV) with a detection limit of 85 pM. This device is based on design principles we have reported previously for detecting proteins via a metalloimmunoassay. It has four desirable attributes. First, its design combines simple origami (paper folding) assembly, the open structure of a hollow-channel paper analytical device to accommodate micrometer-scale particles, and a convenient slip layer for timing incubation steps. Second, two stages of amplification are achieved: silver nanoparticle labels provide a maximum amplification factor of 250 000 and magnetic microbeads, which are mobile solid-phase supports for the capture probes, are concentrated at a detection electrode and provide an additional ∼25-fold amplification. Third, there are no enzymes or antibodies used in the assay, thereby increasing its speed, stability, and robustness. Fourth, only a single sample incubation step is required before detection is initiated.
在此我们展示，通过折纸制作的一种简单的纸质电化学传感器能够检测乙型肝炎病毒（HBV）DNA特有的30个碱基的核苷酸序列，检测限为85皮摩尔。该装置基于我们之前报道的通过金属免疫测定法检测蛋白质的设计原理。它具有四个理想特性。其一，其设计结合了简单的折纸组装、中空通道纸质分析装置的开放结构以容纳微米级颗粒，以及用于定时孵育步骤的便捷滑动层。其二，实现了两个放大阶段：银纳米颗粒标记提供最大250000倍的放大因子，磁性微珠作为捕获探针的可移动固相支持物，集中在检测电极处并提供额外约25倍的放大。其三，该测定法不使用酶或抗体，从而提高了其速度、稳定性和耐用性。其四，在开始检测之前仅需一个样品孵育步骤。
