He Yong-Qiang, Gao Yu, Gu Hui-Wen, Meng Xian-Zhu, Yi Hong-Chao, Chen Ying, Sun Wei-Yin
College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou, 434023, PR China.
College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou, 434023, PR China.
Biosens Bioelectron. 2021 Apr 15;178:113034. doi: 10.1016/j.bios.2021.113034. Epub 2021 Jan 24.
In this work, a sensitive electrochemical method for bleomycin (BLM) determination was reported on the basis of BLM-mediated activation of Zn-dependent DNAzyme and the adsorption of signal probes by a metal-organic framework (MOF) modified electrode. Two hairpin DNAs were employed in this protocol, one (HP1) for BLM recognition and one (HP2) for amplified signal output. The presence of BLM and Fe caused the formation of BLM-Fe (II) complex to cleave HP1, releasing DNAzyme fragments, which could further hybridize with substrate HP2 to form a partial double-stranded DNA duplex and enable the activation of Zn-dependent DNAzyme with the coexistence of Zn. The Zn-dependent DNAzyme catalyzed the cyclic cleavage of magnetic beads (MB)-immobilized HP2 to release massive DNA fragments with a Fc-labeled- terminal, which could be used for BLM quantification through electrochemical measurement after their adsorption on a MOF modified electrode. Attributing to the high catalytic efficiency of DNAzyme and excellent electrochemical performance of MOF modified electrode, our method revealed an impressive limit of detection as low as 4 pM BLM with a linear range of 5-2000 pM. Besides, the easy synthesis of MOF without further modification and the easy way of adsorption for signal achievement facilitated the operation process. In virtue of the high sensitivity, selectivity and the simple-to-implement features, this method is believed to hold a great promising application for BLM determination in biomedical and clinical study.
在本工作中，基于博来霉素（BLM）介导的锌依赖性脱氧核酶激活以及金属有机框架（MOF）修饰电极对信号探针的吸附，报道了一种用于测定博来霉素的灵敏电化学方法。本方案中使用了两条发夹状DNA，一条（HP1）用于识别BLM，另一条（HP2）用于放大信号输出。BLM和铁的存在导致形成BLM-Fe（II）复合物，从而切割HP1，释放出脱氧核酶片段，这些片段可进一步与底物HP2杂交形成部分双链DNA双链体，并在锌共存的情况下激活锌依赖性脱氧核酶。锌依赖性脱氧核酶催化磁珠（MB）固定的HP2的循环切割，释放出大量带有Fc标记末端的DNA片段，这些片段在吸附到MOF修饰电极上后可通过电化学测量用于BLM定量。由于脱氧核酶的高催化效率和MOF修饰电极优异的电化学性能，我们的方法显示出令人印象深刻的检测限，低至4 pM BLM，线性范围为5-2000 pM。此外，MOF易于合成且无需进一步修饰，以及实现信号吸附的简便方法简化了操作过程。凭借高灵敏度、选择性和易于实施的特点，该方法有望在生物医学和临床研究中用于BLM的测定。
