State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University , Changsha, Hunan 410082, China.
Anal Chem. 2015 Mar 3;87(5):2665-71. doi: 10.1021/ac503301q. Epub 2015 Feb 9.
We developed a novel homogeneous fluorescence analysis based on a novel competitive host-guest interaction (CHGI) mechanism between β-cyclodextrin polymer (polyβ CD) and pyrene-labeled probe for biochemical assay. Pyrene labeling with oligonucleotide strands can be recruited and reside in lipophilic cavities of polyβ CD. This altered lipophilic microenvironment provides favored polarity for enhanced quantum efficiencies and extraordinarily increases the luminescence intensity of pyrene. However, with addition of complementary DNA, the pyrene-labeled probe formed double-strand DNA to hinder pyrene from entering the cavities of polyβ CD. The release of pyrene from polyβ CD, which are followed by fluorescence extinguishing, will provide the clear signal turn-off in the presence of target DNA. We also introduced Exodeoxyribonuclease I (Exo I) and Exodeoxyribonuclease III (Exo III) to improve the sensitivity of this system, and the following product of cleavage reaction, pyrene-nucleotide, could more easily host-guest interact with polyβ CD and emit stronger fluorescence than pyrene-labeled probe. In addition, the successful detection of adenosine is also demonstrated by using the similar sensing scheme. Although this scheme might be easily interfered by some biomolecules in the real test sample, it holds promising potential for detecting a broad range of other types of aptamer-binding chemicals and biomolecules.
我们开发了一种基于新型β-环糊精聚合物（polyβ CD）与芘标记探针之间新型竞争主客体相互作用（CHGI）机制的新型均相荧光分析方法，用于生化分析。寡核苷酸链的芘标记可以被招募并驻留在 polyβ CD 的亲脂性空腔中。这种改变的亲脂性微环境为增强的量子效率提供了有利的极性，并极大地增加了芘的荧光强度。然而，随着互补 DNA 的加入，芘标记的探针形成双链 DNA，阻止芘进入 polyβ CD 的空腔。当存在靶 DNA 时，polyβ CD 中释放的芘会导致荧光猝灭，从而提供清晰的信号关闭。我们还引入了 Exodeoxyribonuclease I（Exo I）和 Exodeoxyribonuclease III（Exo III）来提高该系统的灵敏度，并且切割反应的产物，即芘核苷酸，与 polyβ CD 更易发生主客体相互作用，并发出比芘标记探针更强的荧光。此外，还通过类似的传感方案成功检测了腺苷。尽管该方案可能容易受到实际测试样品中一些生物分子的干扰，但它具有检测广泛其他类型适体结合化学物质和生物分子的潜在前景。
