School of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China; College of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211800, PR China.
School of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China.
Biosens Bioelectron. 2018 Aug 15;113:116-123. doi: 10.1016/j.bios.2018.04.062. Epub 2018 May 2.
An ultrasensitive electrochemical genosensor has been fabricated for the double determination of two different specific sequences deduced from the maternally expressed gene3 (MEG3) lncRNA (long noncoding RNA), which was demonstrated by coupling RNase A-aided target recycling with DNA supersandwich-induced signal enhancement, based on a composite interface of graphene-like tungsten disulfide/dendritic gold nanostructures (WS/DGN). Firstly, duple target sequences of T and T were captured by the primer probes of P/P functionalized FeO@C magnetic nanoparticles, via the DNA/RNA hybridization between T/T and P/P. In the presence of RNase A, T and T were released to trigger the target recycling, accompanied by the generation of numerous intermediate DNAs designated as IT and IT, respectively. After the magnetic separation, the IT and IT were liberated and hybridized with the capture probes of CP/CP loaded DGN/WS modified electrode. Subsequently, the stepwise DNA hybridization chain reactions (HCR) labeled with ferrocene (Fc) and methyleneblue (MB) were processed, respectively. The DPV current values of Fc and MB were recorded, which were proportional with the concentration of T and T, respectively. Using the multiplexed amplification strategy, this newly designed genosensor provided a wide linear range from 1 fM to 100 pM with a low detection limit of 0.25 fM for T and 0.3 fM for T. The application of the genosensor in real serum sample has also been studied, confirming the excellent selectivity and sensitivity for the application in bioanalysis and clinical diagnostics.
一种超灵敏的电化学基因传感器已经被制备出来，用于双重测定从母体表达基因 3（MEG3）lncRNA 推导出来的两个不同的特定序列，这是通过将 RNase A 辅助的靶标循环与 DNA 超三明治诱导的信号增强相结合来实现的，基于石墨烯样二硫化钨/树枝状金纳米结构（WS/DGN）的复合界面。首先，T 和 T 的双靶序列被功能化 FeO@C 磁性纳米粒子的引物探针捕获，通过 T/T 和 P/P 之间的 DNA/RNA 杂交。在 RNase A 的存在下，T 和 T 被释放以触发靶标循环，同时产生大量的中间 DNA，分别命名为 IT 和 IT。磁分离后，IT 和 IT 被释放并与负载 DGN/WS 的 CP/CP 捕获探针杂交。随后，分别进行了标记有二茂铁（Fc）和亚甲蓝（MB）的分步 DNA 杂交链反应（HCR）。记录 Fc 和 MB 的 DPV 电流值，它们与 T 和 T 的浓度成正比。使用多重扩增策略，这个新设计的基因传感器提供了从 1 fM 到 100 pM 的宽线性范围，T 的检测限低至 0.25 fM，T 的检测限低至 0.3 fM。该基因传感器在真实血清样本中的应用也得到了研究，证实了其在生物分析和临床诊断中的应用具有优异的选择性和灵敏度。
