Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi, Hubei, 435002, China.
Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, 518055, China.
Small. 2023 Jun;19(23):e2207736. doi: 10.1002/smll.202207736. Epub 2023 Mar 14.
DNA self-assembly has been developed as a kind of robust signal amplification strategy, but most of reported assembly pathways are programmed to amplify signal in one direction. Herein, based on mutual-activated cascade cycle of hybridization chain reaction (HCR) and catalytic hairpin assembly (CHA), a closed cycle circuit (CCC) based DNA machine is developed for sensitive logic operation and molecular recognition. Benefiting from the synergistically accelerated signal amplification, the closed cyclic DNA machine enabled the logic computing with strong and significant output signals even at weak input signals. The typical logic operations such as OR, YES, AND, INHIBIT, NOR, and NAND gate, are conveniently and clearly executed with this DNA machine through rational design of the input and computing elements. Moreover, by integrating the target recognition module with the CCC module, the proposed DNA machine is further employed in the homogeneous detection of apurinic/apyrimidinic endonuclease 1 (APE1). The precise recognition and exponential signal amplification facilitated the highly selective and sensitive detection of APE1 with limit of detection (LOD) of 7.8 × 10 U mL . Besides, the normal cells and tumor cells are distinguished unambiguously by this method according to the detected concentration difference of cellular APE1, which indicates the robustness and practicability of this method.
DNA 自组装已被开发为一种稳健的信号放大策略，但大多数报道的组装途径都被编程为在一个方向上放大信号。在此，基于杂交链式反应（HCR）和催化发夹组装（CHA）的相互激活级联循环，开发了一种基于闭合循环电路（CCC）的 DNA 机器，用于灵敏的逻辑运算和分子识别。得益于协同加速的信号放大，闭环 DNA 机器使逻辑计算即使在弱输入信号下也能产生强而显著的输出信号。通过合理设计输入和计算元件，该 DNA 机器方便、清晰地执行了典型的逻辑运算，如或、是、与、抑制、或非和与非门。此外，通过将靶标识别模块与 CCC 模块集成，该 DNA 机器进一步用于无嘌呤/嘧啶内切核酸酶 1（APE1）的均相检测。精确的识别和指数信号放大促进了 APE1 的高选择性和灵敏检测，检测限（LOD）为 7.8×10 U mL-1。此外，根据细胞 APE1 的检测浓度差异，该方法可以明确地区分正常细胞和肿瘤细胞，表明该方法具有稳健性和实用性。
