Two orders-of-magnitude enhancement in the electrochemiluminescence of Ru(bpy)₃²⁺ by vertically ordered silica mesochannels.
Two orders-of-magnitude enhancement in the electrochemiluminescence of Ru(bpy)₃²⁺ by vertically ordered silica mesochannels.
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DOI：
10.1016/j.aca.2015.06.005
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发表时间：
2015-07
影响因子：
6.2
通讯作者：
Zhenyu Zhou;Weiliang Guo;Linru Xu;Qian Yang;B. Su
中科院分区：
文献类型：
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作者：
Zhenyu Zhou;Weiliang Guo;Linru Xu;Qian Yang;B. Su
在本文中，我们报告了在由垂直排列的二氧化硅介孔道（SMC）组成的薄膜修饰的氧化铟锡（ITO）电极上，三（2, 2′-联吡啶基）钌（II）（Ru（bpy）3 2+）的电化学发光（ECL）显着增强。垂直的 SMC 允许 Ru (bpy) 3 2+ 及其共反应物从溶液到下面的 ITO 电极表面的有效传质。此外，由于SMCs的超小直径（即2-3 nm）和带负电的表面，对带正电的Ru（bpy） 3 2+ 产生强大的静电吸引力，加速其传质，导致ECL信号显着增强。作为模型系统，当使用三正丙胺（TPrA）作为共反应物时，SMCs修饰的ITO电极产生的ECL强度比裸ITO电极强两个数量级以上（即增加约107倍）。在这种情况下，基于ECL的分析所需的Ru(bpy) 3 2+ 的量可以显着减少。极低浓度的Ru (bpy) 3 2+，即9 μM，被证明足以实现TPrA、尼古丁和阿托品的灵敏检测。光电倍增管 (PMT) 和电荷耦合器件 (CCD) 均用于测量 ECL 反应的发光。根据ECL强度测量，获得的检测限为TPrA 0.17 nM，根据捕获的ECL图像的灰度值分析，尼古丁为72 nM，阿托品为38 nM。
In this paper, we report significantly enhanced electrochemiluminescence (ECL) of tris (2, 2′-bipyridyl) ruthenium (II)(Ru (bpy) 3 2+) at indium tin oxide (ITO) electrodes modified with a thin film consisting of vertically aligned silica mesochannels (SMCs). The perpendicular SMCs allow for the effective mass transport of Ru (bpy) 3 2+ and its co-reactants from the solution to the underlying ITO electrode surface. Moreover, due to the ultrasmall diameter (namely 2–3 nm) and the negatively charged surface, SMCs exerted a strong electrostatic attraction to the positively charged Ru (bpy) 3 2+ to accelerate its mass transport, resulting in a remarkably increased ECL signal. As a model system, when using tri-n-propylamine (TPrA) as the co-reactant, the intensity of ECL generated at the SMCs-modified ITO electrode was stronger than that at a bare ITO electrode by more than two orders of magnitude (ie,∼ 107-fold increase). In this case, the amount of Ru (bpy) 3 2+ required for ECL-based analysis can be considerably reduced. A very low concentration of Ru (bpy) 3 2+, namely 9 μM, was demonstrated to be enough for achieving the sensitive detection of TPrA, nicotine and atropine. Both photomultiplier (PMT) and charge coupled device (CCD) were used to measure the luminescence from the ECL reaction. The obtained detection limits were 0.17 nM for TPrA on the basis of the ECL intensity measurement, 72 nM for nicotine and 38 nM for atropine based on the gray value analysis of captured ECL images.