Chen Xueqian, Su Jiyuan, Xiang Dengke, Yuan Zhiqin, Lu Chao
Pingyuan Laboratory, College of Chemistry, Zhengzhou University, Zhengzhou 450001, China.
State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China.
Anal Chem. 2024 Nov 5;96(44):17689-17697. doi: 10.1021/acs.analchem.4c03868. Epub 2024 Oct 23.
The size of gold nanoparticles (AuNPs) largely decides their properties and applications, making the rapid screening of AuNP size important. Despite the fact that AuNP-amplified electrochemiluminescence (ECL) is widely used in various ECL sensing applications, the mechanism of ECL enhancement remains elusive, especially the quantitative relationship between the enhanced ECL intensity and the size of AuNPs. In this work, taking quasispherical and citrate-stabilized AuNPs as model nanoparticles, we have reported that the ECL intensity of the SO-O system enhanced significantly with the increasing AuNP size. AuNPs acted as bielectrocatalysts for reducing the SO and O. The further study of enhancement mechanism demonstrates that AuNPs with increasing size facilitate the electron transfer and promote the generation of radicals required for the ECL emission, which produces more emitters-singlet oxygen. Meanwhile, the high surface density of citrate on small AuNPs suppresses the ECL signal by forming an electrostatic barrier. On the basis of the above phenomena, an ECL-based rapid AuNP size screening approach has been established. The accuracy of this platform is verified by the consistent results in comparison to transmission electron microscopy (TEM) measurements. This work not only provides deep insight into the correlation between the AuNP size and the ECL enhancement but also contributes an alternative to the TEM technique for the rapid AuNP size screening. Additionally, this study also extends the exploration of ECL-based structure analysis techniques toward nanomaterials through clarifying the structure-electrocatalytic activity correlation.
金纳米颗粒（AuNPs）的尺寸在很大程度上决定了它们的性质和应用，因此快速筛选AuNP尺寸很重要。尽管AuNP放大的电化学发光（ECL）广泛应用于各种ECL传感应用中，但ECL增强的机制仍然难以捉摸，尤其是增强的ECL强度与AuNPs尺寸之间的定量关系。在这项工作中，以准球形和柠檬酸盐稳定的AuNPs作为模型纳米颗粒，我们报道了SO-O系统的ECL强度随着AuNP尺寸的增加而显著增强。AuNPs作为双电催化剂用于还原SO和O。对增强机制的进一步研究表明，尺寸增加的AuNPs促进了电子转移并促进了ECL发射所需的自由基的产生，从而产生了更多的发射体——单线态氧。同时，小尺寸AuNPs上柠檬酸盐的高表面密度通过形成静电屏障抑制了ECL信号。基于上述现象，建立了一种基于ECL的快速AuNP尺寸筛选方法。与透射电子显微镜（TEM）测量结果一致，验证了该平台的准确性。这项工作不仅深入了解了AuNP尺寸与ECL增强之间的相关性，还为快速筛选AuNP尺寸的TEM技术提供了一种替代方法。此外，本研究还通过阐明结构-电催化活性相关性，扩展了基于ECL的纳米材料结构分析技术的探索。
