华中师范大学朱成周团队报道了仿生单原子位点实现有效的氧活化，用于切换阳极/阴极电化学发光。相关研究成果于2023年4月21日发表在《德国应用化学》。

开发具有优异氧还原活性的先进共反应加速器，产生丰富的活性氧（ROS），在促进鲁米诺-O₂电化学发光（ECL）方面引起了人们的极大关注。然而，调节用于有效和选择性催化O₂活化的加速器以切换阳极/阴极ECL是非常具有挑战性的。

该文中，研究人员报道了具有轴向N/C配位结构的酶启发的铁基单原子催化剂（FeN₅，FeN₄（C）SACs）可以产生用于阴极/阳极ECL转化的特定ROS。机理研究表明，FeN₅位点更倾向于产生高活性的羟基自由基，并通过N诱导的电子再分配促进O-O键的断裂，从而提供直接的阴极发光。相反，FeN₄（C）位点倾向于产生超氧化物自由基，导致低效的阳极ECL。得益于增强的阴极ECL，构建了基于FeN₅-SAC的免疫传感器，用于敏感检测癌症生物标记物。

附：英文原文

Title: Bioinspired Single-Atom Sites Enable Efficient Oxygen Activation for Switching Anodic/Cathodic Electrochemiluminescence

Author: Weiqing Xu, Yu Wu, Xiaosi Wang, Ying Qin, Hengjia Wang, Zhen Luo, Jing Wen, Liuyong Hu, Wenling Gu, Chengzhou Zhu

Issue&Volume: 2023-04-21

Abstract: Exploring advanced co-reaction accelerators with superior oxygen reduction activity that generate rich reactive oxygen species (ROS) has attracted great attention in boosting luminol-O2 electrochemiluminescence (ECL). However, tuning accelerators for efficient and selective catalytic O2 activation to switch anodic/cathodic ECL is very challenging. Herein, we report that enzyme-inspired Fe-based single-atom catalysts with axial N/C coordination structures (FeN5, FeN4(C) SACs) can generate specific ROS for cathodic/anodic ECL conversion. Mechanistic studies reveal that FeN5 sites prefer to produce highly active hydroxyl radicals and afford direct cathodic luminescence by promoting the cleavage of O-O bonds through N-induced electron redistribution. In contrast, FeN4(C) sites tend to produce superoxide radicals, resulting in inefficient anodic ECL. Benefiting from the enhanced cathodic ECL, FeN5 SAC-based immunosensor was constructed for the sensitive detection of cancer biomarkers.

DOI: 10.1002/anie.202304625

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202304625