Li Dan, Xia Ling, Zhou Qianjiang, Wang Ling, Chen Dongmei, Gao Xin, Li Yang
School of Chemistry and Chemical Engineering, Guizhou University, No. 2708, South Section of Huaxi Avenue, Guiyang, Guizhou 550025, China.
School of Physics, Guizhou University, No. 2708, South Section of Huaxi Avenue, Guiyang, Guizhou550025, China.
Anal Chem. 2020 Oct 6;92(19):12769-12773. doi: 10.1021/acs.analchem.0c03335. Epub 2020 Sep 22.
miRNA plays a vital role in many biological processes by regulating the expression of target genes and is considered to be a promising disease biomarker. Although surface-enhanced Raman spectroscopy (SERS) has been widely used for the detection of nucleic acid molecules, obtaining a characteristic SERS signal of unlabeled RNA in a nondestructive state still remains a challenge. Herein, titanium ions were used as aggregating agents to induce the aggregation of silver nanoparticles, forming hot spots, and the fingerprint information on miRNAs was successfully obtained. This method was used to determine the RNA sequence of homopolymeric bases and the peak position of each base in the Raman spectrum. The obtained RNA spectrum was normalized with the signal intensity of ribose at 959 cm, and the base contents of a series of mature miRNA sequences were quantified. Subsequently, the characteristic SERS signal of the RNA hybridization event was obtained by studying the process of RNA hairpin structure formation, and the role of the precursor mir-21 in regulating the target streptomycin sulfate was successfully analyzed. The changes in the SERS signal intensity at the interaction site were accurately identified. This method has potential applications in biological functions of miRNAs, molecular diagnosis, disease treatment, and targeted drug design.
微小RNA（miRNA）通过调控靶基因的表达在许多生物学过程中发挥着至关重要的作用，并且被认为是一种很有前景的疾病生物标志物。尽管表面增强拉曼光谱（SERS）已被广泛用于核酸分子的检测，但在无损状态下获得未标记RNA的特征性SERS信号仍然是一个挑战。在此，钛离子被用作聚集剂来诱导银纳米颗粒聚集，形成热点，并成功获得了miRNA的指纹信息。该方法用于确定同聚物碱基的RNA序列以及拉曼光谱中每个碱基的峰位置。所获得的RNA光谱用959 cm处核糖的信号强度进行归一化，并对一系列成熟miRNA序列的碱基含量进行了定量。随后，通过研究RNA发夹结构的形成过程获得了RNA杂交事件的特征性SERS信号，并成功分析了前体mir-21在调控靶标硫酸链霉素中的作用。准确识别了相互作用位点处SERS信号强度的变化。该方法在miRNA的生物学功能、分子诊断、疾病治疗和靶向药物设计方面具有潜在应用。
