Key Laboratory of Laboratory Medical Diagnostics of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, 400016, PR China; Department of Clinical Laboratory, People's Hospital of Changshou Chongqing, Chongqing, 401220, PR China.
Key Laboratory of Laboratory Medical Diagnostics of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, 400016, PR China; Department of Clinical Laboratory, The Central Hospital of Fuling Chongqing, Chongqing, 408099, PR China.
Biosens Bioelectron. 2020 Feb 15;150:111964. doi: 10.1016/j.bios.2019.111964. Epub 2019 Dec 13.
Rapid and efficient detection of tumor marker at the early stages is one of the crucial challenges in cancer diagnostics and therapy. In this study, an ultrasensitive electrochemical biosensor was fabricated by dual-amplified strategy for the detection of ultra-trace microRNA-141 (miRNA-141). Firstly, two split sequences contained G-quadruplex were connected by click chemistry-mediated nucleic acid strands self-assembly and the obtained complete G-quadruplex was complementary with miRNA-141 to formed DNA-RNA hybrid duplexes. Subsequently, the formed DNA-RNA hybrid duplexes were specifically recognized by duplex-specific nuclease (DSN), and the DNA part of the duplexes were cleaved and the miRNA-141 were released to trigger next cycle, which acquired a primal signal amplification by enzyme-assisted target recycling (EATR). Moreover, amino and thiol group multi-labeled functionalized fullerene nanoparticles (FC60) with a larger surface active sites and better biocompatibility, were designed rationally to modify the Au electrodes, which produced multiply-enhanced amplified signal. This dual-amplified sensing system exhibited a remarkable analytical performance for the detection of miRNA-141 in concentrations ranging from 0.1 pM to 100 nM and the detection limit of 7.78 fM was obtained. Compared with the biosensor with single amplification strategy such as EATR, this electrochemical biosensor based on dual-amplified strategy exhibited an excellent discrimination capability and higher analytical performance. Therefore, this electrochemical biosensor might hold a great potential for further applications in biomedical research and early clinical diagnosis.
在癌症诊断和治疗中，早期快速有效地检测肿瘤标志物是一个关键挑战。在本研究中，通过双扩增策略构建了一种超灵敏电化学生物传感器，用于检测超痕量 microRNA-141（miRNA-141）。首先，通过点击化学介导的核酸链自组装将两个包含 G-四链体的分裂序列连接起来，得到的完整 G-四链体与 miRNA-141互补形成 DNA-RNA 杂交双链。随后，形成的 DNA-RNA 杂交双链被双链特异性核酸酶（DSN）特异性识别，双链的 DNA 部分被切割，miRNA-141 被释放，从而触发下一个循环，通过酶辅助靶标循环（EATR）实现初始信号放大。此外，设计了具有更多表面活性位点和更好生物相容性的多标记功能化富勒烯纳米粒子（FC60）来合理修饰 Au 电极，从而产生多重增强的放大信号。该双扩增传感系统对 miRNA-141 的检测表现出显著的分析性能，检测浓度范围为 0.1 pM 至 100 nM，检测限为 7.78 fM。与基于 EATR 的单扩增策略的生物传感器相比，基于双扩增策略的电化学生物传感器具有出色的区分能力和更高的分析性能。因此，这种电化学生物传感器可能在生物医学研究和早期临床诊断中有很大的应用潜力。
