Highly sensitive free radical detection by nitrone-functionalized gold nanoparticles.
Highly sensitive free radical detection by nitrone-functionalized gold nanoparticles.
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DOI：
10.1039/c3nr04559e
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发表时间：
2014-01
期刊：
影响因子：
6.7
通讯作者：
L. Du;Saipeng Huang;Qianfen Zhuang;Hongying Jia;A. Rockenbauer;Yangping Liu;Ke-Jian Liu;Yang Liu-Yang-L
中科院分区：
文献类型：
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作者：
L. Du;Saipeng Huang;Qianfen Zhuang;Hongying Jia;A. Rockenbauer;Yangping Liu;Ke-Jian Liu;Yang Liu-Yang-L
近年来，自由基及其相关物种的检测因其在生理和病理过程中的重要作用而备受关注。在检测自由基的方法中，电子自旋共振(ESR)结合自旋捕捉技术因其高度的特异性而成为表征和定量这些物种的有效方法。然而，它在生物体系中的应用，特别是在活体体系中的应用，一直受到极大的限制，部分原因是目前可用的自旋陷阱与生物自由基之间的反应速度很慢。为了克服这一缺点，我们在此报告了第一个硝酮功能化的金纳米颗粒(Au@EMPO)作为高效自旋陷阱的例子，其中硫代化的EMPO(1-氧化物(2-(ethoxycarbonyl)-2-methyl-3，4-dihydro-2H-pyrrole)衍生物自组装到金纳米颗粒上。动力学研究表明，Au@EMPO与·OH的反应速率常数是PbN(N-叔丁基-α-苯基硝酮)的137倍。由于Au@EMPO对·OH有很高的捕获率以及生成的自旋加合物具有很高的稳定性(tç∼56min)，所以Au@EMPO对·OH的灵敏度是EMPO的124倍。因此，这种新的纳米自旋陷阱在捕获各种生物体系中的重要自由基如·OH方面显示出巨大的潜力，并为设计具有更高性能的自旋陷阱提供了一种新的策略。
The detection of free radicals and related species has attracted significant attention in recent years because of their critical roles in physiological and pathological processes. Among the methods for the detection of free radicals, electron spin resonance (ESR) coupled with the use of the spin trapping technique has been an effective approach for characterization and quantification of these species due to its high specificity. However, its application in biological systems, especially in in vivo systems, has been greatly limited partially due to the low reaction rate between the currently available spin traps with biological radicals. To overcome this drawback, we herein report the first example of nitrone functionalized gold nanoparticles (Au@EMPO) as highly efficient spin traps in which the thiolated EMPO (2-(ethoxycarbonyl)-2-methyl-3,4-dihydro-2H-pyrrole 1-oxide) derivative was self-assembled on gold nanoparticles. Kinetic studies showed that Au@EMPO has a 137-fold higher reaction rate constant with ˙OH than PBN (N-tert-butyl-α-phenylnitrone). Owing to the high rate of trapping ˙OH by Au@EMPO as well as the high stability of the resulting spin adduct (t½ ∼ 56 min), Au@EMPO affords 124-fold higher sensitivity for ˙OH than EMPO. Thus, this new nanospin trap shows great potential in trapping the important radicals such as ˙OH in various biological systems and provides a novel strategy to design spin traps with much improved properties.