Key Laboratory of Chem-Biosensing, Anhui province; Key Laboratory of Functional Molecular Solids, Anhui province; College of Chemistry and Materials Science, Anhui Normal University , Wuhu 241000, People's Republic of China.
Langmuir. 2013 Nov 19;29(46):14328-34. doi: 10.1021/la403192p. Epub 2013 Nov 4.
In the present study, based on multifunctional Dual-Hairpin DNA structure, a simple, fast and high sensitive assay for the detection of DNA, thrombin and adenosine triphosphate (ATP) was demonstrated. DNA sequence labeled with methylene blue (MB), which was designed as single-stranded DNA (ssDNA) matching with target DNA, thrombin, or ATP aptamer, hybridized to the adjunct probe and formed the dual-hairpin structure on the electrode. With the hybridization of adjunct probe and the hairpin-like capture probe in the stem region, the dual-hairpin was formed with outer and inner hairpins. By the conjugation of the target probe with the adjunct probe in the outer hairpin, the adjunct probe divorced from the dual-hairpin structure. The adjunct probe with signal molecules MB, attaching near or divorcing far from the electrode, produced electrochemical signal change and efficient electron transfer due to the fact that it was in proximity to the electrode. However, upon hybridization with the perfect match target, the redox label with the target probe was forced away from the modified electrode, thus resulting in the change of the Dual-Hairpin DNA conformation, which enables impedance of the efficient electron transfer of MB and, consequently, a detectable change of the electrochemical response. In addition, another highlight of this biosensor is its regenerability and stability owing to the merits of structure. Also, based on this Dual-Hairpin platform, the detection limits of DNA, thrombin, and ATP were 50 nM, 3 pM, and 30 nM, respectively. Moreover, this pattern also demonstrated excellent regenerability, reproducibility, and stability. Additionally, given to its ease-of-use, simplicity in design, easy operations, as well as regenerability and stability, the proposed approach may be applied as an excellent design prompter in the preparation of other molecular sensors.
在本研究中，基于多功能双发夹 DNA 结构，我们展示了一种用于检测 DNA、凝血酶和三磷酸腺苷 (ATP) 的简单、快速和高灵敏的方法。用亚甲基蓝 (MB) 标记的 DNA 序列设计为与靶 DNA、凝血酶或 ATP 适体匹配的单链 DNA (ssDNA)，与辅助探针杂交并在电极上形成双发夹结构。随着辅助探针与茎区发夹状捕获探针的杂交，形成了外发夹和内发夹的双发夹。通过目标探针与外发夹中的辅助探针的缀合，辅助探针从双发夹结构中脱离。带有信号分子 MB 的辅助探针由于靠近或远离电极而附着或离开发夹结构，从而产生电化学信号变化和有效的电子转移。然而，当与完全匹配的靶杂交时，带有靶探针的氧化还原标记物被迫远离修饰电极，从而导致双发夹 DNA 构象发生变化，这使得 MB 的有效电子转移的阻抗发生变化，从而导致电化学响应的可检测变化。此外，由于结构的优点，该生物传感器的另一个亮点是其可再生性和稳定性。此外，基于该双发夹平台，DNA、凝血酶和 ATP 的检测限分别为 50 nM、3 pM 和 30 nM。此外，该模式还表现出出色的再生性、重现性和稳定性。此外，鉴于其易于使用、设计简单、操作简便、可再生性和稳定性，该方法可作为其他分子传感器制备的优秀设计提示。
