Confined Electrochemiluminescence Generation at Ultra-High-Density Gold Microwell Electrodes.
Confined Electrochemiluminescence Generation at Ultra-High-Density Gold Microwell Electrodes.
复制标题
超高密度金微孔电极产生受限电化学发光
DOI：
10.3389/fchem.2020.630246
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发表时间：
2020
影响因子：
5.5
通讯作者：
Su B
中科院分区：
文献类型：
--
作者：
Ding J;Zhou P;Guo W;Su B
基于超高密度微孔电极阵列（UMEA）的电化学发光（ECL）成像分析已经成功地应用于生物传感和诊断领域，但对ECL产生机制的空间分辨率研究仍然很少。本文采用化学沉积法制备了一种金包覆的聚二甲基硅氧烷（PDMS） UMEA，并结合微观ECL成像技术，在单微孔水平上可视化ECL反应过程，证明了微孔金壁确实能够增强ECL的生成。对于包含三（2,2′-联吡啶）钌（Ru(bpy) 32 +）和三正丙胺（TPrA）的经典ECL体系，单个微井的ECL图像呈现为一个表面受限的环，表明井内产生的ECL强度远高于UMEA顶表面的ECL强度。此外，在低浓度Ru(bpy) 32 +下，随着暴露时间的增加，ECL图像仍然呈环状，这是由于TPrA自由基阳离子TPrA+•的寿命有限。结合理论模拟，分析了环形ECL图像来源于微井壁和井底表面质量扩散场的叠加效应。
Electrochemiluminescence (ECL) imaging analysis based on the ultra-high-density microwell electrode array (UMEA) has been successfully used in biosensing and diagnostics, while the studies of ECL generation mechanisms with spatial resolution remain scarce. Herein we fabricate a gold-coated polydimethylsiloxane (PDMS) UMEA using electroless deposition method for the visualization of ECL reaction process at the single microwell level in conjunction with using microscopic ECL imaging technique, demonstrating that the microwell gold walls are indeed capable of enhancing the ECL generation. For the classical ECL system involving tris(2,2′-bipyridyl)ruthenium (Ru(bpy)3 2+) and tri-n-propylamine (TPrA), the ECL image of a single microwell appears as a surface-confined ring, indicating the ECL intensity generated inside the well is much stronger than that on the top surface of UMEA. Moreover, at a low concentration of Ru(bpy)3 2+, the ECL image remains to be ring-shaped with the increase of exposure time, because of the limited lifetime of TPrA radical cations TPrA+•. In combination with the theoretical simulation, the ring-shaped ECL image is resolved to originate from the superposition effect of the mass diffusion fields at both microwell wall and bottom surfaces.