DNA-templated silver nanoparticles as a platform for highly sensitive and selective fluorescence turn-on detection of dopamine.
DNA-templated silver nanoparticles as a platform for highly sensitive and selective fluorescence turn-on detection of dopamine.
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DOI：
10.1002/smll.201002351
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发表时间：
2011-06
期刊：
影响因子：
13.3
通讯作者：
Youhui Lin;Meili Yin;Fang Pu;Jinsong Ren;Xiaogang Qu
中科院分区：
文献类型：
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作者：
Youhui Lin;Meili Yin;Fang Pu;Jinsong Ren;Xiaogang Qu
Youhui Lin，Meili Yin，Fang Pu，Jinsong Ren，* and Xiaogang Qu* 在该地区DA完全耗尽。[7a]由于DA的生理和病理生理效应范围广泛，因此精确的DA测定具有重要的临床意义。DA具有电化学活性，在过去的几十年中，通过电化学方法对其进行测定引起了特别的关注。[9]然而，共存的物质，如抗坏血酸（AA）和尿酸（UA），在接近DA的电位下被氧化，可能会干扰DA的检测。其他方法，如毛细管电泳与激光诱导天然荧光[10]和高效液相色谱-质谱法，也被用于解决灵敏度问题。[11]然而，这些协议都有时间密集、昂贵和通常需要专用设备的缺点。随着纳米技术的发展，新的检测方法被用于DA的检测。[9，12]例如，Lin et al. [12b]报道了一种通过利用介孔二氧化硅材料内部的分子识别来选择性检测DA的策略。然而，它们受到灵敏度的限制，并且只能检测到微摩尔浓度的DA。在此，我们首次描述了使用DNA介导的银纳米结构作为简单、可靠、高灵敏度和选择性的DA荧光开启检测平台。DNA对银离子具有高亲和力，并且这些局部阳离子可以被还原以形成遵循DNA模板轮廓的银纳米结构。[2a因此，DNA支架中银纳米颗粒的形成将阻断以嵌入方式结合DNA的配体的结合，并且当一些配体嵌入银吸附的DNA中时，还可以用作荧光猝灭剂。另一方面，最近发现DA通过形成Ag-邻苯二酚键而与银纳米颗粒表现出有趣的反应性。[13]我们的策略受到这些现象的启发，方案1描述了该方法。最初，化学吸附在银纳米结构上的DA将从银表面释放DNA，这归因于较强的Ag-儿茶酚相互作用。在某些嵌入染料的存在下，在与DNA结合时将观察到荧光的显著增加，其可以用作定量释放的DNA的报告物。[14]由于DNA被DA从银表面释放后，嵌入染料的荧光强度显著增强，因此利用所观察到的荧光变化，可以实现DA的开启型荧光传感器。
Youhui Lin, Meili Yin, Fang Pu, Jinsong Ren,* and Xiaogang Qu* complete depletion of DA in this region.[7a] Given the wide range of physiological and pathophysiological effects of DA, precise DA determination is of great clinical importance. DA is electrochemically active and its determination by electrochemical methods has attracted special attention during the past few decades.[9] However, coexisting species such as ascorbic acid (AA) and uric acid (UA), which are oxidized at potentials close to that of DA, can interfere with the detection of DA. Other approaches, such as capillary electrophoresis with laser-induced native fluorescence [10] and high-performance liquid chromatography–mass spectrometry, have also been used to address the sensitivity.[11] However, these protocols share the drawbacks of being time-intensive, expensive, and usually requiring specialized equipment. With the developments in nanotechnology, new methods have been used for the detection of DA.[9, 12] For instance, Lin et al.[12b] reported a strategy for the selective detection of DA by exploiting molecular recognition inside mesoporous silica materials. However, they were limited by the sensitivity, and only micromolar concentrations of DA were detectable.Herein, for the first time, we describe the use of a DNA-mediated silver nanostructure as a platform for simple, reliable, highly sensitive and selective fluorescence turn-on detection of DA. DNA has a high affinity for silver ions, and these localized cations could be reduced to form silver nanostructures that follow the contour of the DNA template.[2a, 4] Therefore, the formation of silver nanoparticles in the DNA scaffold would block the binding of ligands that bind to DNA intercalatively, and may also work as a fluorescence quencher when some of the ligands intercalate in the silver-adsorbed DNA. On the other hand, DA was recently found to exhibit intriguing reactivity with silver nanoparticles by forming Ag–catechol bonds.[13] Our strategy was inspired by these phenomena and the approach is depicted in Scheme 1. Initially, the chemisorbed DA on the silver nanostructures would release the DNA from the silver surface, which is attributable to the stronger Ag–catechol interaction. In the presence of certain intercalating dyes, a dramatic increase in fluorescence would be observed upon binding to the DNA, which could serve as a reporter to quantitate the released DNA.[14] Since the fluorescence intensity of intercalating dyes is significantly enhanced after DNA is released from the silver surface by DA, a turn-on fluorescence sensor for DA could be realized by taking advantage of the observed fluorescence change.