Polydiacetylene liposome arrays for selective potassium detection
Polydiacetylene liposome arrays for selective potassium detection
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DOI：
10.1021/ja709996c
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发表时间：
2008-04-16
影响因子：
15
通讯作者：
Kim, Jinsang
中科院分区：
文献类型：
--
作者：
Lee, Jiseok;Kim, Hyong-Jun;Kim, Jinsang
钾离子是生物体内重要的阳离子，对细胞外钾离子水平的定量检测具有重要意义。然而，由于钠的浓度高得多，选择性检测细胞外生理钾是一项具有挑战性的任务。在这方面的贡献，我们描述了实用的聚丁二炔（PDA）脂质体为基础的微阵列的发展，选择性地检测钾，即使在钠的存在下。我们利用的事实是，富含G的ssDNA可以折叠成G-四链体通过分子内氢键通过包裹周围的钾离子排。我们合理地设计了PDA脂质体，使富含G的ssDNA探针密集地存在于脂质体表面，并在与K+结合时形成庞大的四链体。所得到的庞大的四链体是空间位阻的，并且彼此排斥，并在PDA主链上施加机械应力，导致PDA的烯-炔主链的构象变化。结果，聚二乙炔脂质体从非荧光蓝相转变为发射红色相。
Potassium is an important cation in biology, and quantitative detection of the extracellular potassium level is important. However, selective detection of extracellular physiological potassium is a challenging task due to the presence of sodium in a much higher concentration. In this contribution, we describe the development of practical polydiacetylene (PDA) liposome-based microarrays to selectively detect potassium even in the presence of sodium. We utilize the fact that the G-rich ssDNA can fold into a G-quadruplex via intramolecular hydrogen bonding by wrapping around a potassium ion exclusively. We rationally design the PDA liposome in such a way that the G-rich ssDNA probes are presented densely at the liposome surface and form bulky quadruplexes upon binding with K+. The resulting bulky quadruplexes are sterically hindered and repulse each other and impose mechanical stress on the PDA backbone, resulting in the conformational change of the ene-yne backbone of the PDA. As a result, polydiacetylene liposomes turn into the emissive red phase from the nonfluorescent blue phase.