Fitzpatrick Institute for Photonics, Departments of Biomedical Engineering and Chemistry, Duke University, Durham, NC 27708, USA.
Small. 2011 Nov 4;7(21):3067-74. doi: 10.1002/smll.201101380. Epub 2011 Sep 12.
A label-free approach using plasmonic coupling interference (PCI) nanoprobes for nucleic acid detection using surface-enhanced Raman scattering (SERS) is described. To induce a strong plasmonic coupling effect, a nanonetwork of silver nanoparticles with the Raman label located between adjacent nanoparticles is assembled by Raman-labeled DNA-locked nucleic acid (LNA) duplexes. The PCI method then utilizes specific nucleic acid sequences of interest as competitor elements for the Raman-labeled DNA strands to interfere the formation of nanonetworks in a competitive binding process. As a result, the plasmonic coupling effect induced through the formation of the nanonetworks is significantly diminished, resulting in a reduced SERS signal. The potential of the PCI technique for biomedical applications is illustrated by detecting single-nucleotide polymorphism (SNP) and microRNA sequences involved in breast cancers. The results of this study could lead to the development of nucleic acid diagnostic tools for biomedical diagnostics and biosensing applications using SERS detection.
本文描述了一种使用等离子体耦合干涉（PCI）纳米探针的无标记方法，通过表面增强拉曼散射（SERS）进行核酸检测。为了诱导强烈的等离子体耦合效应，通过拉曼标记的 DNA-锁核酸（LNA）双链组装具有拉曼标记的银纳米粒子的纳米网络，该拉曼标记位于相邻纳米粒子之间。然后，PCI 方法利用感兴趣的特定核酸序列作为竞争元素，通过竞争结合过程干扰拉曼标记的 DNA 链形成纳米网络。结果，通过形成纳米网络诱导的等离子体耦合效应显著减弱，导致 SERS 信号减少。通过检测涉及乳腺癌的单核苷酸多态性（SNP）和 microRNA 序列，说明了 PCI 技术在生物医学应用中的潜力。本研究的结果可能会导致开发用于生物医学诊断和生物传感应用的核酸诊断工具，使用 SERS 检测。
