Tao Feng, Fang Jie, Guo Yongcan, Tao Yiyi, Han Xinle, Hu Yuxin, Wang Jinjing, Li Luyuan, Jian Yulin, Xie Guoming
Key Laboratory of Laboratory Medical Diagnostics, Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, 400016, PR China.
Clinical Laboratory of Traditional Chinese Medicine Hospital Affiliated to Southwest Medical University, Luzhou, 646000, PR China.
Anal Biochem. 2018 Aug 1;554:16-22. doi: 10.1016/j.ab.2018.05.024. Epub 2018 May 30.
Hepatitis B virus (HBV), one of the causative agents of viral hepatitis, may lead to chronic hepatitis, cirrhosis, and liver cancer. In this work, we designed a sensitive and modular biosensing platform for detecting HBV DNA based on a DNA walker that hangs on to surfaces and a catalyst-triggered catalyzed hairpin assembly (CHA). In the presence of HBV DNA, strand displacement reaction between target and double-stranded complex caused the release of walker strand to trigger the DNA walker. Then, a catalyst was free to open the trapped hairpins to form a new double-strand complex, driving the CHA reaction. Thus, a powerful cascade amplification reaction realized in DNA walker and CHA based on toehold-mediated strand displacement reaction in this system. To achieve quantitative detection of HBV DNA, a fluorescent-quencher signaling pair was employed, the turn-on fluorescence provided an analytical signal. A wide detection range from 0.5 nM to 50 nM with a detection limit as low as 0.20 nM was reached on the condition of acceptable specificity and reproducibility. We could also further apply it to multiple different bioanalysis by changing adjustable elements. This reported biosensor opened a new avenue for sensitivity and modularity of DNA detection.
乙型肝炎病毒（HBV）是病毒性肝炎的致病因子之一，可能导致慢性肝炎、肝硬化和肝癌。在这项工作中，我们基于附着在表面的DNA步行器和催化剂触发的催化发夹组装（CHA）设计了一种用于检测HBV DNA的灵敏且模块化的生物传感平台。在存在HBV DNA的情况下，靶标与双链复合物之间的链置换反应导致步行链释放，从而触发DNA步行器。然后，催化剂能够打开被捕获的发夹以形成新的双链复合物，驱动CHA反应。因此，在该系统中基于链置换反应在DNA步行器和CHA中实现了强大的级联放大反应。为了实现对HBV DNA的定量检测，采用了荧光-猝灭信号对，开启的荧光提供了分析信号。在可接受的特异性和重现性条件下，实现了0.5 nM至50 nM的宽检测范围，检测限低至0.20 nM。通过改变可调元件，我们还可以进一步将其应用于多种不同的生物分析。这种报道的生物传感器为DNA检测的灵敏度和模块化开辟了一条新途径。
