Ngo Hoan T, Wang Hsin-Neng, Fales Andrew M, Vo-Dinh Tuan
Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA.
Fitzpatrick Institute for Photonics, Duke University, Durham, NC, 27708, USA.
Anal Bioanal Chem. 2016 Mar;408(7):1773-81. doi: 10.1007/s00216-015-9121-4. Epub 2015 Nov 7.
The development of rapid, cost-effective DNA detection methods for molecular diagnostics at the point-of-care (POC) has been receiving increasing interest. This article reviews several DNA detection techniques based on plasmonic-active nanochip platforms developed in our laboratory over the last 5 years, including the molecular sentinel-on-chip (MSC), the multiplex MSC, and the inverse molecular sentinel-on-chip (iMS-on-Chip). DNA probes were used as the recognition elements, and surface-enhanced Raman scattering (SERS) was used as the signal detection method. Sensing mechanisms were based on hybridization of target sequences and DNA probes, resulting in a distance change between SERS reporters and the nanochip's plasmonic-active surface. As the field intensity of the surface plasmon decays exponentially as a function of distance, the distance change in turn affects SERS signal intensity, thus indicating the presence and capture of the target sequences. Our techniques were single-step DNA detection techniques. Target sequences were detected by simple delivery of sample solutions onto DNA probe-functionalized nanochips and measuring the SERS signal after appropriate incubation times. Target sequence labeling or washing to remove unreacted components was not required, making the techniques simple, easy-to-use, and cost-effective. The usefulness of the nanochip platform-based techniques for medical diagnostics was illustrated by the detection of host genetic biomarkers for respiratory viral infection and of the dengue virus gene.
开发用于即时医疗（POC）分子诊断的快速、经济高效的DNA检测方法越来越受到关注。本文综述了过去5年我们实验室基于等离子体活性纳米芯片平台开发的几种DNA检测技术，包括芯片上分子哨兵（MSC）、多重MSC和芯片上反向分子哨兵（iMS-on-Chip）。DNA探针用作识别元件，表面增强拉曼散射（SERS）用作信号检测方法。传感机制基于靶序列与DNA探针的杂交，导致SERS报告分子与纳米芯片的等离子体活性表面之间的距离发生变化。由于表面等离子体的场强随距离呈指数衰减，距离变化进而影响SERS信号强度，从而表明靶序列的存在和捕获。我们的技术是单步DNA检测技术。通过将样品溶液简单地滴加到DNA探针功能化的纳米芯片上，并在适当的孵育时间后测量SERS信号来检测靶序列。不需要对靶序列进行标记或洗涤以去除未反应的成分，使得这些技术简单、易用且具有成本效益。通过检测呼吸道病毒感染的宿主遗传生物标志物和登革热病毒基因，说明了基于纳米芯片平台的技术在医学诊断中的实用性。
