Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
Talanta. 2018 Jun 1;183:108-113. doi: 10.1016/j.talanta.2018.02.063. Epub 2018 Feb 15.
In the present work, we designed a unique enzyme-aided multiple amplification strategy for sensitive electrochemiluminescence (ECL) detection of DNA by using the amplified gold nanoparticles (GNPS)-polyamidoamine (PAMAM)-CdSe quantum dots (QDs) signal probe. Firstly, the novel GNPS-PAMAM dendrimers nanostructure with good biocompatibility and electroconductibility contains many amino groups, which can load a large number of CdSe QDs to develop amplified ECL signal probe. Then, the presence of target DNA activated the enzyme-assisted polymerization strand-displacement cycling reaction, and a large number of the hairpin template was opened. Subsequently, the opened stem further interacted with the capture hairpin (HP) DNA on the electrode, and the GNPS-PAMAM-CdSe signal probe hybridized with the exposed stem of the HP to trigger the second new polymerization reaction. Meanwhile, the first cycle was generating abundant DNA triggers which could directly open the template. As a result of the cascade amplification technique, a large number of CdSe QDs signal probe could be assembled on the electrode, generating much amplified ECL signal for sensitive detection of target DNA. Thus, this novel QDs-based amplified ECL strategy holds great promise for DNA detection and can be further exploited for sensing applications in clinical diagnostics.
在本工作中，我们设计了一种独特的酶辅助多重扩增策略，用于通过使用放大的金纳米粒子 (GNPS)-聚酰胺胺 (PAMAM)-CdSe 量子点 (QDs) 信号探针灵敏地电化学发光 (ECL) 检测 DNA。首先，具有良好生物相容性和导电性的新型 GNPS-PAMAM 树枝状纳米结构包含许多氨基，可负载大量的 CdSe QDs 以开发放大的 ECL 信号探针。然后，目标 DNA 的存在激活了酶辅助聚合链置换循环反应，并打开了大量的发夹模板。随后，打开的茎进一步与电极上的捕获发夹 (HP) DNA 相互作用，GNPS-PAMAM-CdSe 信号探针与 HP 的暴露茎杂交，引发第二个新的聚合反应。同时，第一轮反应会产生大量的 DNA 触发物，可直接打开模板。由于级联扩增技术，大量的 CdSe QDs 信号探针可以组装在电极上，产生大量的放大 ECL 信号，从而对目标 DNA 进行灵敏检测。因此，这种新型基于 QDs 的放大 ECL 策略在 DNA 检测方面具有很大的应用前景，并可进一步用于临床诊断中的传感应用。
