College of Liberal Arts and Sciences, National University of Defense Technology.
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University.
Anal Sci. 2020 Jul 10;36(7):835-840. doi: 10.2116/analsci.19P387. Epub 2020 Jan 24.
Sensitive and specific detection of nucleic acids or proteins, which act as biomarkers, is of great importance in disease diagnosis. By combing the concept and operation of an endonuclease-assisted target-responsive amplification method and peroxidase-mimic DNAzyme generated by terminal deoxynucleotidyl transferase (TdT), a novel and facile colorimetric biosensor was developed for DNA and protein. Target DNA and thrombin were chosen as representative biomolecules. The production of cleavage fragments can only be triggered by specific target binding and the following nicking process, which do not occur spontaneously. In the signal collection part, numerous guanine-rich DNA were produced through the prolongation of cleavage fragments by TdT and formed highly effective DNAzyme with hemin. In this novel amplification method, we succeeded in realizing sensitive and specific detection of target DNA and thrombin. Under optimal conditions, target DNA can be detected as low as 1 pM, and thrombin with a detection limit of 100 pM. The method also proves the potential versatility and feasibility of TdT-generated DNAzyme in various bio-analyses.
灵敏且特异地检测核酸或蛋白质（作为生物标志物）在疾病诊断中具有重要意义。通过结合内切酶辅助靶标响应扩增方法的概念和操作以及末端脱氧核苷酸转移酶（TdT）产生的过氧化物酶模拟 DNA 酶，开发了一种用于 DNA 和蛋白质的新型简便比色生物传感器。靶 DNA 和凝血酶被选为代表性生物分子。只有在特定靶标结合和随后的切口过程中才能触发切割片段的产生，而这些过程不会自发发生。在信号收集部分，通过 TdT 对切割片段进行延伸产生了大量富含鸟嘌呤的 DNA，并与血红素形成了高效的 DNA 酶。在这种新型扩增方法中，我们成功地实现了对靶 DNA 和凝血酶的灵敏和特异性检测。在最佳条件下，可检测到低至 1 pM 的靶 DNA，凝血酶的检测限为 100 pM。该方法还证明了 TdT 产生的 DNA 酶在各种生物分析中的潜在多功能性和可行性。
