Feng Qiumei, Wang Mengying, Han Xiguang, Chen Qian, Dou Baoting, Wang Po
School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou 221116, China.
ACS Appl Bio Mater. 2020 Feb 17;3(2):1276-1282. doi: 10.1021/acsabm.9b01145. Epub 2020 Feb 6.
A critical challenge for improving the detection performance of sensors is building a favorable sensing interface. Herein, an innovative electrochemical biosensing system relying on hierarchical mesoporous NiO@N-doped C microspheres coupled with catalytic hairpin assembly was developed for DNA analysis. In this strategy, the utilization of NiO@N-doped C microspheres and multiwalled carbon nanotubes as electrode materials effectively enhanced the interfacial electron transfer and improved the surface active sites for subsequent reactions. By designing a target-assisted catalytic hairpin assembly, single target DNA could initiate the introduction of multiple signal probes labeled with ferrocene (Fc) onto a working electrode surface. Because the change in the Fc signal is dependent on the amount of target DNA, the resulting electrochemical sensing platform is highly sensitive. Under optimized reaction conditions, this testing platform has a wide linear range for target DNA detection from 100 aM to 100 pM with a detection limit of 45 aM. Furthermore, the platform displayed excellent selectivity, acceptable reproducibility, and long-term stability, highlighting the application potential of this sensing system.
提高传感器检测性能的一个关键挑战是构建一个良好的传感界面。在此，开发了一种基于分级介孔NiO@N掺杂C微球并结合催化发夹组装的创新型电化学生物传感系统用于DNA分析。在该策略中，利用NiO@N掺杂C微球和多壁碳纳米管作为电极材料有效地增强了界面电子转移，并改善了后续反应的表面活性位点。通过设计目标辅助催化发夹组装，单链目标DNA可引发多个标记有二茂铁（Fc）的信号探针在工作电极表面的引入。由于Fc信号的变化取决于目标DNA的量，因此所构建的电化学传感平台具有高灵敏度。在优化的反应条件下，该测试平台对目标DNA的检测具有从100 aM到100 pM的宽线性范围，检测限为45 aM。此外，该平台表现出优异的选择性、可接受的重现性和长期稳定性，突出了该传感系统的应用潜力。
