High-Entropy Single-Atom Catalyst as Coreactant Accelerator for Reactive Oxygen Species-Mediated Electrochemiluminescence

promote weak binding with intermediates. The unique electronic structure and synergistic interaction among the HE-SAC metal active sites enhance the catalytic activity, boosting ROS production. The interactions between active sites and the graphenic support leverage high entropy to further boost the HE-SAC durability and catalytic efficiency. Furthermore, the incorporation of luminol-modified AgNPs with HE-SAC significantly enhances the ECL signal, resulting in a 5.9-fold increase compared with single Fe-SAC under optimal conditions, strongly aligning with theoretical DFT prediction. As a proof of concept, the acquired ECL biosensor was fruitfully applied to the ultrasensitive detection of miRNA-21. The regulation of high-entropy single heteroatoms offers a pioneering approach to accelerate intermediate generation for boosting coreactant ECL systems.