Miao Peng, Wang Bidou, Chen Xifeng, Li Xiaoxi, Tang Yuguo
†CAS Key Lab of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China.
‡University of Chinese Academy of Sciences, Beijing 100049, China.
ACS Appl Mater Interfaces. 2015 Mar 25;7(11):6238-43. doi: 10.1021/acsami.5b01508. Epub 2015 Mar 10.
MicroRNAs are not only important regulators of a wide range of cellular processes but are also identified as promising disease biomarkers. Due to the low contents in serum, microRNAs are always difficult to detect accurately . In this study, an electrochemical biosensor for ultrasensitive detection of microRNA based on tetrahedral DNA nanostructure is developed. Four DNA single strands are engineered to form a tetrahedral nanostructure with a pendant stem-loop and modified on a gold electrode surface, which largely enhances the molecular recognition efficiency. Moreover, taking advantage of strand displacement polymerization, catalytic recycling of microRNA, and silver nanoparticle-based solid-state Ag/AgCl reaction, the proposed biosensor exhibits high sensitivity with the limit of detection down to 0.4 fM. This biosensor shows great clinical value and may have practical utility in early diagnosis and prognosis of certain diseases.
微小RNA不仅是多种细胞过程的重要调节因子，还被确定为有前景的疾病生物标志物。由于血清中含量低，微小RNA总是难以准确检测。在本研究中，开发了一种基于四面体DNA纳米结构的用于超灵敏检测微小RNA的电化学生物传感器。四条DNA单链被设计成具有悬垂茎环的四面体纳米结构，并修饰在金电极表面，这大大提高了分子识别效率。此外，利用链置换聚合、微小RNA的催化循环以及基于银纳米颗粒的固态Ag/AgCl反应，所提出的生物传感器表现出高灵敏度，检测限低至0.4 fM。这种生物传感器具有很大的临床价值，可能在某些疾病的早期诊断和预后中具有实际应用。
