In traditional luminol-H2O2 electrochemiluminescence (ECL) sensing platform, H2O2 suffers from the self-decomposition of at room temperature, inevitably leading to the difficulty for quantitative analysis. In this work, we first adopt iron single-atom catalysts (Fe-N-C SACs) as an advanced coreactant accelerator to directly reduce the dissolved oxygen (O2) into reactive oxygen species (ROS). Owing to the unique electronic structure and catalytic activity of Fe-N-C SACs, a large amount of ROS could be efficiently produced, which will react with the luminol anion radical and significantly amplif...