Huang Yuqi, Zhao Shuhui, Zhang Wenxiu, Duan Qiuyue, Yan Qi, Fu Hu, Zhong Liang, Yi Gang
Key Laboratory of Medical Diagnostics of Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University Chongqing 400016 PR China
Clinical Laboratory of Chengdu First People's Hospital Chengdu 610000 PR China.
RSC Adv. 2021 Jun 4;11(33):20046-20056. doi: 10.1039/d1ra02424h. eCollection 2021 Jun 3.
Nucleic acids are genetic materials in the human body that play important roles in storing, copying, and transmitting genetic information. Abnormal nucleic acid sequences, base mutations, and genetic changes often lead to cancer and other diseases. Meanwhile, methylated DNA is one of the main epigenetic modifications, which is considered to be an excellent biomarker in the early detection, prognosis, and treatment of cancers. Therefore, a multifunctional electrochemical biosensor was constructed with sturdy tetrahedral tripods, which assisted multiple tandem hairpins through base complementary pairing and effective ultra-sensitive detection of targets (DNA, microRNA, and methylated DNA). In the experiments, experimental conditions were optimized, and different DNA concentrations in serum were detected to verify the sensitivity of the biosensor and the feasibility of this protocol. In addition, microRNA and DNA methylation were detected through different designs of tetrahedral tripods (TTs) that capture probes to prove the superiority of this scheme. A sturdy pyramid structure of TTs extremely enhanced the capture efficiency of targets. The targets triggered the one-step isothermal multi-tandem amplification reaction by incubating multiple hairpin assemblies. To our knowledge, a combination of two parts, which greatly reduced background interference and decreased non-specific substance interference, has appeared for the first time in this paper. Moreover, the load area of electrochemical substances was significantly increased than that in previous studies. This greatly increased the detection range and detection limit of targets. The electrochemical signal responses were generated in freely diffusing hexaammineruthenium(iii) chloride (RuHex). RuHex could adhere to the DNA phosphate backbone by a powerful electrostatic attraction, causing increased current responses.
核酸是人体中的遗传物质，在存储、复制和传递遗传信息方面发挥着重要作用。异常的核酸序列、碱基突变和基因变化常常导致癌症和其他疾病。同时，甲基化DNA是主要的表观遗传修饰之一，被认为是癌症早期检测、预后和治疗中的一种优秀生物标志物。因此，构建了一种具有坚固四面体三脚架的多功能电化学生物传感器，其通过碱基互补配对辅助多个串联发夹，并对靶标（DNA、微小RNA和甲基化DNA）进行有效的超灵敏检测。在实验中，优化了实验条件，检测了血清中不同浓度的DNA，以验证生物传感器的灵敏度和该方案的可行性。此外，通过捕获探针的四面体三脚架（TTs）的不同设计检测微小RNA和DNA甲基化，以证明该方案的优越性。TTs的坚固金字塔结构极大地提高了靶标的捕获效率。通过孵育多个发夹组装体，靶标触发了一步等温多串联扩增反应。据我们所知，本文首次出现了两个部分的组合，这大大降低了背景干扰并减少了非特异性物质干扰。此外，电化学物质的负载面积比以前的研究显著增加。这大大提高了靶标的检测范围和检测限。在自由扩散的六氨合钌（III）氯化物（RuHex）中产生了电化学信号响应。RuHex可以通过强大的静电引力附着在DNA磷酸主链上，导致电流响应增加。
