Treerattrakoon Kiatnida, Roeksrungruang Pimporn, Dharakul Tararaj, Japrung Deanpen, Faulds Karen, Graham Duncan, Bamrungsap Suwussa
National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Pathumthani 12120, Thailand.
Department of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, 99 George Street, Glasgow, UK.
Anal Methods. 2022 May 27;14(20):1938-1945. doi: 10.1039/d2ay00210h.
Detection of miR-29a, a biomarker of cancers, using SERS tags and magnetic separation is described. The assay was designed to detect the miR-29a sequence by taking the complementary sequence and splitting it into a capture and detection probe. The SERS tags comprised the highly Raman active molecule 4-mercaptobenzoic acid (4-MBA) and DNA detection probes assembled onto the surface of gold nanorods (AuNRs) through the self-assembly process. The capture DNA conjugated magnetic nanoparticles (MNPs) were applied as capture probes. The detection was based on the hybridisation and sandwich complex formation. The resultant hybridisation-dependent complexes were recovered and enriched from the samples by magnetic separation. The enriched solution containing target miRNA hybridised with capture probes were dropped on a foil-covered slide to form a droplet for SERS analysis. A characteristic spectrum of 4-MBA was observed to indicate the presence of the miR-29a in the samples. The sensitivity of the assay is examined by measuring the SERS signal of the samples containing different concentrations of the miR-29a. The SERS intensity appears to increase with the concentration of miR-29a. The limit of detection (LOD) was found to be 10 pM without any amplification process. In addition, the selectivity and feasibility of the assay in complex media are evaluated with the non-target miRNAs comprising different sequences from the target miR-29a. The system was capable of detecting the target miR-29a specifically with high selectivity. These results suggest that this solution-based SERS platform has a significant capability for simple, sensitive, and selective miR-29a analysis.
本文描述了使用表面增强拉曼散射（SERS）标签和磁分离技术检测癌症生物标志物miR-29a的方法。该检测方法通过获取互补序列并将其拆分为捕获探针和检测探针来检测miR-29a序列。SERS标签由高拉曼活性分子4-巯基苯甲酸（4-MBA）和通过自组装过程组装在金纳米棒（AuNRs）表面的DNA检测探针组成。捕获DNA偶联的磁性纳米颗粒（MNPs）用作捕获探针。检测基于杂交和夹心复合物的形成。通过磁分离从样品中回收并富集所得的杂交依赖性复合物。将含有与捕获探针杂交的靶标miRNA的富集溶液滴在覆盖有箔的载玻片上形成液滴用于SERS分析。观察到4-MBA的特征光谱表明样品中存在miR-29a。通过测量含有不同浓度miR-29a的样品的SERS信号来检测该检测方法的灵敏度。SERS强度似乎随着miR-29a浓度的增加而增加。发现检测限（LOD）为10 pM，无需任何扩增过程。此外，用包含与靶标miR-29a不同序列的非靶标miRNA评估该检测方法在复杂介质中的选择性和可行性。该系统能够以高选择性特异性地检测靶标miR-29a。这些结果表明，这种基于溶液的SERS平台具有用于简单、灵敏和选择性分析miR-29a的显著能力。
