Jiangsu Collaborative Innovation Centre of Biomedical Functional Materials and Jiangsu Key Laboratory of Biofunctional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, PR China; School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164, USA; School of Environment, Nanjing Normal University, Nanjing 210023, PR China.
School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164, USA.
Biosens Bioelectron. 2017 Aug 15;94:56-62. doi: 10.1016/j.bios.2017.02.044. Epub 2017 Feb 27.
MicroRNAs (miRNAs) play important roles in gene regulation and cancer development. Nowadays, it is still a challenge to detect low-abundance miRNAs. Here, we present a magnetic fluorescent miRNA sensing system for the rapid and sensitive detection of miRNAs from cell lysates and serum samples. In this system, albumin nanoparticles (Alb NPs) were prepared from inherent biocompatible bovine serum albumin (BSA). A large number of fluorescent dyes were loaded into Alb NPs to make Alb NPs serve as signal molecular nanocarriers for signal amplification. Benefited from the reactive functional groups-carboxyl groups of Alb NPs, p19 protein, a viral protein that can bind and sequester short RNA duplex effectively and selectively, was modified successfully to the surface of the fluorescent dyes-loaded Alb NPs, thus enabling the probe:target miRNA duplex recognition and binding. Followed by the introduction of gold nanoparticles coated magnetic microbeads (Au NPs-MBs), which were prepared through a novel and simple method, the system combined the merits of the rapid and efficient collection given by MBs with the good affinities to attach probe molecules endowed by the coated gold layer. A broad linear detection range of 10fM-10nM and a low detection limit of 9fM were obtained within 100min by detecting a model target miRNA-21. The feasibility of this method for rapid and sensitive quantification might advance the use of miRNAs as biomarkers in clinical praxis significantly.
微小 RNA（miRNAs）在基因调控和癌症发展中发挥着重要作用。目前，检测低丰度 miRNAs 仍然是一个挑战。在这里，我们提出了一种用于快速灵敏检测细胞裂解物和血清样本中 miRNAs 的磁性荧光 miRNA 传感系统。在该系统中，白蛋白纳米颗粒（Alb NPs）是由固有生物相容性牛血清白蛋白（BSA）制备的。大量荧光染料被加载到 Alb NPs 中，使 Alb NPs 作为信号分子纳米载体进行信号放大。受益于 Alb NPs 的反应性功能基团-羧基，p19 蛋白，一种可以有效且选择性地结合和隔离短 RNA 双链的病毒蛋白，成功地修饰到荧光染料负载的 Alb NPs 的表面，从而使探针：靶 miRNA 双链能够识别和结合。随后引入通过一种新颖且简单的方法制备的涂覆有金纳米粒子的磁性微球（Au NPs-MBs），该系统结合了 MBs 快速高效收集的优点以及涂覆的金层赋予的良好结合探针分子的亲和力。通过检测模型靶标 miRNA-21，在 100min 内获得了 10fM-10nM 的宽线性检测范围和 9fM 的低检测限。这种快速灵敏定量方法的可行性可能会显著推动 miRNA 作为临床实践中生物标志物的应用。
