Department of Dermatology, Guangzhou Institute of Dermatology, Guangzhou 510095, PR China.
Biosens Bioelectron. 2011 Jan 15;26(5):2018-24. doi: 10.1016/j.bios.2010.08.079. Epub 2010 Sep 9.
In this article, we describe an ultrasensitive nucleic acid biosensor (NAB) based on horseradish peroxidase (HRP)-gold nanoparticle (Au-NP) dual labels and lateral flow strip biosensor (LFSB). The results presented here expand on prior work (Mao et al., 2009a) by optimizing the preparation of HRP-Au-NP-DNA conjugates. It was found that sodium dodecyl sulfate (SDS) and the immobilization sequence of thiolated DNA and HRP on the Au-NP surface played very important roles to improve the sensitivity of the assay. After systematic optimization, the detection limit of current approach is 1000 times lower than that in prior work. Deposition of insoluble enzymatic catalytic product (red colored chromogen) on the captured Au-NPs at the test zone of LFSB offers a dramatic visual enhancement. Combining enzyme catalytic amplification with unique optical properties of Au-NPs, the NAB was capable of detecting of 0.01-pM target DNA without instrumentation. The NAB thus provides a rapid, sensitive, low-cost tool for the detection of nucleic acid samples. It shows great promise for in-field and point-of-care diagnosis of genetic diseases and for the detection of infectious agents.
在本文中，我们描述了一种基于辣根过氧化物酶（HRP）-金纳米粒子（Au-NP）双重标记和横向流动条生物传感器（LFSB）的超灵敏核酸生物传感器（NAB）。这里呈现的结果通过优化 HRP-Au-NP-DNA 缀合物的制备扩展了先前的工作（Mao 等人，2009a）。结果表明，十二烷基硫酸钠（SDS）和巯基化 DNA 和 HRP 在 Au-NP 表面的固定化顺序对于提高测定的灵敏度起着非常重要的作用。经过系统优化，当前方法的检测限比先前工作低 1000 倍。在 LFSB 的测试区域中，不溶性酶催化产物（红色显色剂）在捕获的 Au-NP 上的沉积提供了明显的视觉增强。通过将酶催化扩增与 Au-NP 的独特光学性质相结合，NAB 能够在没有仪器的情况下检测到 0.01-pM 的目标 DNA。因此，NAB 为核酸样本的检测提供了一种快速、灵敏、低成本的工具。它在现场和即时护理诊断遗传疾病以及检测传染病方面具有很大的应用前景。
