P-Doped Cu–N–C Single-Atom Catalysts Boost Cathodic Electrochemiluminescence of Luminol for MicroRNA-320d Detection

作者：Ruifang Liu, Shujing Wang, Longfei Zhu, Chengxiang Li, Lixin Xie, Jinxiang Wu, Shenguang Ge, Jinghua Yu · 发表于：Analytical Chemistry · 年份：2025 · DOI：10.1021/acs.analchem.5c03547 · 被引用次数：7 · 研究领域：Advanced biosensing and bioanalysis techniques、Electrochemical Analysis and Applications、Electrocatalysts for Energy Conversion

Compared with efficient anodic luminol electrochemiluminescence (ECL), the disadvantage of cathodic ECL is that luminol cannot be electrochemically oxidized in a direct manner, and the conversion efficiency of dissolved oxygen (DO) as the coreactant to reactive oxygen species (ROS) is poor, which limits its application. Therefore, it is necessary to develop a functional catalyst suitable for the luminol-DO ECL system to directly trigger cathodic ECL. In this study, a coordination microenvironment modulation strategy was proposed. The heteroatom P was doped into the Cu single-atom catalyst (P/Cu SAs@CN), significantly enhancing the cathodic ECL emission in the luminol-DO system. The P/Cu SAs@CN catalyst facilitates a three-electron oxygen reduction reaction pathway, generating abundant ROS, particularly hydroxyl radicals, that amplify the ECL emission by oxidizing luminol anions. Simultaneously, a dual-signal amplification biosensor is developed by integrating APE1 enzyme-mediated target recycling and DNAzyme-catalyzed cleavage cycles. The biosensor achieves ultrasensitive detection of miRNA-320d, a biomarker of metastatic colorectal cancer, with the detection limit of 0.158 fM. This work not only elucidates the mechanistic link between the ORR-driven ROS generation and the ECL enhancement but also provides a versatile platform for designing advanced coreaction accelerators, which can help to address the critical demands in clinical diagnostics.