Browsing by Author "Xiong, Dinghui"

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    Efficient DNA walker guided by ordered cruciform-shaped DNA track for ultrasensitive and rapid electrochemical detection of lead ion
    (Elsevier, 2024-03-20) Zhu, Nuanfei; Wang, Kaixuan; Xiong, Dinghui; Xiao, Jiaxuan; Deng, Yibin; Yang, Zhugen; Zhang, Zhen
    The rational design of DNA tracks is an effective pathway to guide the autonomous movement and high-efficiency recognition in DNA walkers, showing outstanding advantages for the cascade signal amplification of electrochemical biosensors. However, the uncontrolled distance between two adjacent tracks on the electrode could increase the risk of derailment and interruption of the reaction. Hence, a novel four-way balanced cruciform-shaped DNA track (C-DNT) was designed as a structured pathway to improve the effectiveness and stability of the reaction in DNA walkers. In this work, two kinds of cruciform-shaped DNA were interconnected as a robust structure that could avoid the invalid movement of the designed DNA walker on the electrode. When hairpin H2 was introduced onto the electrode, the strand displacement reaction (SDR) effectively triggered movements of the DNA walker along the cruciform-shaped track while leaving ferrocene (Fc) on the electrode, leading to a significant enhancement of the electrochemical signal. This design enabled the walker to move in an excellent organized and controllable manner, thus enhancing the reaction speed and walking efficiency. Compared to other walkers moving on random tracks, the reaction time of the C-DNT-based DNA walker could be reduced to 20 min. Lead ion (Pb2+) was used as a model target to evaluate the analytical performance of this biosensor, which exhibited a low detection limit of 0.033 pM along with a wide detection ranging from 0.1 pM to 500 nM. This strategy presented a novel concept for designing a high-performance DNA walker-based sensing platform for the detection of contaminants.
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    Targeted enrichment of nucleic acid bionic arms enhances the hydrolysis activity of nanozymes for degradation and real-time monitoring of organophosphorus pesticides in water
    (American Chemical Society, 2025-01-28) Zhou, Jialong; Xiong, Dinghui; Zhang, Hu; Xiao, Jiaxuan; Huang, Rui; Qiao, Ze; Yang, Zhugen; Zhang, Zhen
    Organophosphorus pesticides (OPs) pose significant environmental and health risks, and their detoxification through catalytic hydrolysis using zirconium-based metal-organic frameworks (Zr-MOFs) has attracted considerable interest due to the strong Lewis acid metal ions. Albeit important, the defects of the materials for OP hydrolysis (e.g., poor degradation efficiency, rate, and selectivity) limit their further application. Herein, a nucleic acid bionic arm-modified biomimetic nanozyme (MOF-808-Apt) was designed through a Zr-MOF and a specific aptamer against OPs, which was employed for the efficient and selective degradation of OPs. At the system, the functionalized biomimetic nanozyme can continuously capture trace OPs onto its catalytic sites for degradation with the fabricated nucleic acid bionic arms, significantly improving their catalytic activities compared to bare MOF-808 using paraoxon as a model of OPs, providing better performances including (i) an excellent degradation efficiency, boosting from 4 to over 60% within 6 min; (ii) a satisfactory catalytic rate (the pseudo-first-order rate constants of paraoxon hydrolysis improved from 0.09 to 0.14 min-1); and (iii) good selective degradation because of aptamers used. Besides, this dynamic degradation process could be visually recorded in real time with high sensitivity (limit of detection, 0.18 μM) because of the obvious color change of the reaction solution and signal amplification ascribed to increasing local concentrations of targets by the nucleic acid bionic arms. Summarily, this work provides a new strategy for the effective and selective degradation of typical OPs and concurrent monitoring of their dynamic degradation process.