Durable Single-Atom Catalysts Enable Precise Chemiluminescence Tracing.

Single-atom catalysts (SACs) have displayed remarkable merits in bioassays due to their superior catalytic performance. Nevertheless, the durability of both their catalytic activity and detection signal remains a great challenge due to the self-limited behavior of single-atom centers. Herein, Co SACs were synthesized via a template-assisted polymerization using dopamine as a ligand precursor, which provided electron-rich anchoring sites for single-atom Co centers. The designed Co SACs exhibited high activity in catalyzing typical luminol-H2O2 chemiluminescence (CL) reaction under both alkaline and neutral conditions and thus triggered intensive signal for CL detection. Experimental results and density functional theory calculations uncovered the electron transfer from phenolic hydroxyls with delocalized π-electrons to single-atom Co centers, which recovered their catalytic activity and could ensure the durability of the CL signal. The persistent CL signal supplied precise imaging protocols for in situ visualizing the molecular information under working conditions, which was demonstrated by real-time tracing the process of alkaline phosphatase-triggered dephosphorylation for revealing the inhibition of self-limited reaction to enzymatic activity, and monitoring the molecular changes on cell membrane during drug treatment. This work opens an avenue to design durable SACs via an internal electron-driven pathway for improving the accuracy of in situ CL tracing technologies.