Semi-transparent platinum electrodes were designed and optimized to implement photoluminescence (PL) and electrochemiluminescence (ECL) in microchannels under flow conditions. The luminescence properties of tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)) were used to map steady-state emitted light through semi-transparent microchannel electrodes. Several diffusive-convective regimes were thus imposed in order to experimentally highlight the operating conditions of the electrodes, in particular the active zones at their upstream edges contributing to the Faradaic current. PL and ECL profiles were established on the electrode surfaces as a function of flow rate. The PL profiles confirmed the control of the process by mass transport. The data were validated by numerical simulations within the limits of experimental accuracy. ECL emission in presence of the co-reactant tri--propylamine (TPA) was also limited by mass transport. However, in comparison the characteristics of the ECL profiles demonstrated the complexity of the underlying mechanism involving Ru(bpy) regeneration and TPA consumption.

中文翻译：

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强调层流下微通道电极的工作状态：通过半透明电极映射光致发光和电化学发光


半透明铂电极经过设计和优化，可在流动条件下在微通道中实现光致发光（PL）和电化学发光（ECL）。利用三(2,2'-联吡啶基)钌(II) (Ru(bpy)) 的发光特性来绘制通过半透明微通道电极的稳态发射光。因此，施加了几种扩散-对流状态，以便通过实验突出电极的工作条件，特别是其上游边缘处对法拉第电流有贡献的活性区域。在电极表面上建立了 PL 和 ECL 曲线作为流速的函数。 PL 曲线证实了质量传输对过程的控制。在实验精度范围内通过数值模拟验证了数据。存在共反应物三丙胺 (TPA) 时的 ECL 发射也受到传质的限制。然而，相比之下，ECL 曲线的特征证明了涉及 Ru(bpy) 再生和 TPA 消耗的潜在机制的复杂性。