The Key Laboratory of Life-Organic Analysis, Qufu Normal University, Qufu, Shandong, 273165, China.
The Key Laboratory of Pharmaceutical Intermediates and Analysis of Natural Medicine, Qufu Normal University, Qufu, Shandong, 273165, China.
Anal Bioanal Chem. 2018 Mar;410(8):2211-2219. doi: 10.1007/s00216-018-0887-z. Epub 2018 Jan 31.
In this paper, fluorescent Ag nanoclusters (Ag NCs) templated by hyperbranched polyethyleneimine (PEI) are utilized as a versatile probe through the photoinduced electron transfer (PET) between PEI-Ag NCs and G-quadruplex-hemin complexes. In the presence of hemin and target molecule, the specific conjugation with its aptamer induces the conformational change of the DNA sequence, releasing the G-quadruplex sequence part. Once the G-quadruplex-hemin complexes are introduced, electron transfer from the PEI-Ag NCs to G-quadruplex-hemin complexes occurs, resulting in fluorescence quenching. Through changing the sensing DNA sequence, this novel PET system enables the specific detection of target DNA and adenosine triphosphate (ATP) with the wide linear range of 1-200 nM and 5-500 nM, respectively, and the corresponding limit of detection as low as 0.3 nM for target DNA and 1.5 nM for ATP. In addition, the proposed method is successfully applied to the determination of ATP in human serum samples with satisfactory recoveries, and a logic gate is fabricated using target molecules and hemin as inputs and the fluorescence signal of PEI-Ag NCs as an output.
本文利用超支化聚乙烯亚胺（PEI）模板化的荧光 Ag 纳米团簇（Ag NCs）作为一种多功能探针，通过 PEI-Ag NCs 与 G-四链体-血红素复合物之间的光诱导电子转移（PET）实现。在血红素和靶分子存在的情况下，其适体的特异性结合诱导 DNA 序列发生构象变化，释放 G-四链体序列部分。一旦引入 G-四链体-血红素复合物，就会发生从 PEI-Ag NCs 到 G-四链体-血红素复合物的电子转移，导致荧光猝灭。通过改变传感 DNA 序列，该新型 PET 系统能够特异性检测目标 DNA 和三磷酸腺苷（ATP），其线性范围分别为 1-200 nM 和 5-500 nM，相应的检测限低至 0.3 nM 的目标 DNA 和 1.5 nM 的 ATP。此外，该方法成功应用于人血清样品中 ATP 的测定，回收率令人满意，并且使用靶分子和血红素作为输入，PEI-Ag NCs 的荧光信号作为输出，构建了逻辑门。
