Reactivity mapping of luminescence in space: Insights into heterogeneous electrochemiluminescence bioassays
Reactivity mapping of luminescence in space: Insights into heterogeneous electrochemiluminescence bioassays
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DOI：
10.1016/j.bios.2020.112372
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发表时间：
2020-10-01
影响因子：
12.6
通讯作者：
Sojic, Neso
中科院分区：
文献类型：
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作者：
Dutta, Priyanka;Han, Dongni;Sojic, Neso
电化学发光(ECL)是一种基于光学读出的强大的(生物)分析方法。利用该模型和最广泛使用的ECL体系，它被成功地应用于免疫分析和成像的异相格式，该体系包括以三丙胺(TPA)为共反应物的固定化Plu(Bpy)(3)[(2+)](2+)标记。然而，一个主要的缺点是ECL强度随着时间的推移显著降低。在这里，为了解释ECL信号的这种渐进性损失的过程，我们通过在单个微米级微珠的水平上绘制发光反应性图来研究它的电化学和光物理性质。用[Ru(Bpy)(3)](2+)染料通过夹心免疫分析或多肽键对聚苯乙烯小球进行功能化。ECL发射是在非常有效的TPA共反应物存在的情况下产生的。通过成像Plu(Bpy)(3)](2)(+)修饰微珠的不同区域(靠近或远离电极表面)的光致发光和ECL反应性，我们可以展示ECL标记的非凡光物理稳定性，即使在非常活跃的电生TPA自由基存在的情况下也是如此。我们发现ECL的消失与较低的TPA氧化电流直接相关。最后，我们提出了一种简单的电化学处理方法，允许再生电极表面，从而恢复几倍于初始强ECL信号。反应性成像方法提供了对ECL机理和影响发射稳定性的主要因素的深入了解，这将在生物分析和显微技术中找到有前途的ECL应用。
Electrochemiluminescence (ECL) is a powerful (bio)analytical method based on an optical readout. It is successfully applied in the heterogeneous format for immunoassays and imaging using the model and most widely used ECL system, which consists of the immobilized Plu(bpy)(3)](2+) label with tripropylamine (TPA) as a coreactant. However, a major drawback is the significant decrease of the ECL intensity over time. Herein, to decipher the process responsible for this progressive loss of ECL signal, we investigated its electrochemical and photophysical properties by mapping the luminescence reactivity at the level of single micrometric beads. Polystyrene beads were functionalized by the [Ru(bpy)(3)](2+) dye via a sandwich immunoassay or a peptide bond. ECL emission was generated in presence of the very efficient TPA coreactant. Imaging both photoluminescence and ECL reactivities of different regions (located near or far from the electrode surface) of a Plu(bpy)(3)](2)(+)-decorated bead allows us to demonstrate the remarkable photophysical stability of the ECL label, even in presence of the very reactive electrogenerated TPA radicals. We show that the ECL vanishing correlates directly with the lower TPA oxidation current. Finally, we propose a simple electrochemical treatment, which allows to regenerate the electrode surface and thus to recover several times the strong initial ECL signal. The reactivity imaging approach provides insights into the ECL mechanism and the main factors governing the stability of the emission, which should find promising ECL applications in bioassays and microscopy.