Cheng Yu-Hong, Liu Si-Jia, Jiang Jian-Hui
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, PR China.
Guangxi Collaborative Innovation Center for Biomedicine, Guangxi Key Laboratory of Regenerative Medicine, Key Laboratory of Longevity and Aging-related Diseases of Chinese Ministry of Education, School of Basic Medical Sciences, Center for Translational Medicine, Guangxi Medical University, Nanning, 530021, PR China.
Talanta. 2021 Jan 15;222:121536. doi: 10.1016/j.talanta.2020.121536. Epub 2020 Aug 25.
The ability to recognize mRNA with high efficiency in cells would greatly facilitate the elucidation of mRNA-mediated cellular cascades and their disease associations. However, most traditional electrochemical strategies targeting nucleotides are always confronted with cumbersome interface operation and washing procedures, as well as the high cost of labeling and the strict reaction conditions of tool enzymes, limiting their potential applications. To address these issues, herein we reported, for the first time, a simple label-free, isothermal, non-enzymatic, and ultrasensitive homogeneous electrochemical biosensor based on autonomous proximity-dependent surface hybridization chain reaction (HCR), for sensitive signal amplification and highly specific detection of target survivin mRNA with a detection limit of 3 fM. The target triggers hybridization chain reaction and mRNA-fueled surface hybridization of ferrocene-tagged metastable DNA hairpin probes on proximity-dependent surface hybridization, resulting in the formation of multiple long-range duplex DNA chains which are immobilized onto the gold electrodes with a substantially stable ferrocene-mediated redox current. Thus, a significant electrochemical signal increase is observed dependent on the concentration of the target RNA, with a very low detection limit. Mo-reover, this molecular biosensor also exhibits excellent specificity to distinguish even single base mismatched, with strong reliability. The developed biosensor provides a novel promising tool for ultra-sensitive and selective detection, and it has great potential to be applied in mRNA-related biochemical research and clinical cancer diagnostics in more detail.
在细胞中高效识别信使核糖核酸（mRNA）的能力将极大地促进对mRNA介导的细胞级联反应及其与疾病关联的阐释。然而，大多数针对核苷酸的传统电化学策略总是面临繁琐的界面操作和洗涤程序，以及标记成本高和工具酶反应条件苛刻等问题，限制了它们的潜在应用。为了解决这些问题，我们首次报道了一种基于自主邻近依赖性表面杂交链式反应（HCR）的简单、无标记、等温、非酶促且超灵敏的均相电化学生物传感器，用于灵敏的信号放大和对目标生存素mRNA的高特异性检测，检测限为3飞摩尔（fM）。在邻近依赖性表面杂交中，靶标触发杂交链式反应以及二茂铁标记的亚稳态DNA发夹探针的mRNA驱动的表面杂交，导致形成多个长程双链DNA链，这些双链DNA链通过二茂铁介导的基本稳定的氧化还原电流固定在金电极上。因此，观察到电化学信号随靶标RNA浓度显著增加，检测限非常低。此外，这种分子生物传感器对区分甚至单个碱基错配也表现出优异的特异性，可靠性强。所开发的生物传感器为超灵敏和选择性检测提供了一种新颖且有前景的工具，并且在更详细的mRNA相关生物化学研究和临床癌症诊断中具有巨大的应用潜力。
