Surface Plasmon Resonance Imaging Detection of Sub-femtomolar MicroRNA
Surface Plasmon Resonance Imaging Detection of Sub-femtomolar MicroRNA
复制标题
亚飞摩尔微小RNA的表面等离子共振成像检测
DOI：
10.1021/acs.analchem.7b02838
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发表时间：
2017
影响因子：
7.4
通讯作者：
Chen Yi
中科院分区：
文献类型：
--
作者：
Hu Feichi;Xu Jiying;Chen Yi
microRNA（miRNA）是一种很有前途的新型生物标志物，但其fM水平较低，难以分析。本文提出了一种创新的表面等离子体共振成像（SPRi）方法，该方法结合了新型的平面内和垂直信号放大策略，即正交信号放大，以能够直接测定亚fM miRNA-15 a（多种肿瘤诊断生物标志物）。其核心思想是先沿着表面方向，然后从表面向上，在目标采样点上添加更多的质量。在miRNA的检测中，这通过将miRNA引发的表面环状DNA-DNA杂交反应与DNA引发的向上环状聚合反应偶联来实现。制备了一种完美的SPRi传感芯片，其具有由疏水CYTOP包围的隔离金岛，并用于以低的制造难度获得高质量的芯片。因此，SPRi对比度大大增加，能够达到miRNA-15 a的检测限和定量限低至0.56和5 fM，与普通SPRi检测相比，灵敏度提高约107倍。该方法可用于人血清中标准miRNA-15 a的定量，回收率在98.6%~ 104.9%之间，适用于健康人和癌症患者血清中miRNA-15 a的直接测定。有序和可控的原位敏化策略是强大的，并且容易扩展到其他miRNA的检测。
MicroRNA (miRNA) is a promising new type of biomarkers but at a low fM level and hard to be analyzed. Herein proposed is an innovated surface plasmon resonance imaging (SPRi) method merged with a novel in-plane and vertical signal amplification strategy, that is, orthogonal signal amplification to enable a direct determination of sub-fM miRNA-15a (a multiple tumor diagnostic biomarker). The core idea is to add more mass on a target sample spot first along the surficial direction, then upward from the surface. In detection of miRNA, this was realized by coupling a miRNA-initiated surficial cyclic DNA–DNA hybridization reaction with a DNA-initiated upward cyclic polymerization reaction. A perfect SPRi sensing chip with isolated gold islands bordered by hydrophobic CYTOP was fabricated and used to obtain high-quality chip with low fabrication difficulty. As a result, SPRi contrast largely increases, able to reach a limit of detection and limit of quantification down to 0.56 and 5fM for miRNA-15a, about 107-fold improvement of sensitivity compared with a common SPRi detection. The method could quantify standard miRNA-15a spiked in human serum with an ideal recovery ranging from 98.6% to 104.9% and was validated to be applicable to the direct determination of miRNA-15a in healthy and cancer human serums. The orderly and controllable in situ sensitizing strategy is powerful and readily extendable to detection of other miRNAs.