Tuning Local Coordination Environments of Manganese Single‐Atom Nanozymes with Multi‐Enzyme Properties for Selective Colorimetric Biosensing

Single‐atom nanozymes (SAzymes) are promising in next‐generation nanozymes, nevertheless, how to rationally modulate the microenvironment of SAzymes with controllable multi‐enzyme properties is still challenging. Herein, we systematically investigate the relationship between atomic configuration and multi‐enzymatic performances. The constructed MnSA−N3‐coordinated SAzymes (MnSA−N3−C) exhibits much more remarkable oxidase‐, peroxidase‐, and glutathione oxidase‐like activities than that of MnSA−N4−C. Based on experimental and theoretical results, these multi‐enzyme‐like behaviors are highly dependent on the coordination number of single atomic Mn sites by local charge polarization. As a consequence, a series of colorimetric biosensing platforms based on MnSA−N3−C SAzymes is successfully built for specific recognition of biological molecules. These findings provide atomic‐level insight into the microenvironment of nanozymes, promoting rational design of other demanding biocatalysts. A new strategy for achieving the multi‐enzymatic performance of SAzymes through regulating the coordination number of heterogeneous manganese single‐atom catalysts (MnSA−Nx−C) is designed and implemented. A series of colorimetric biosensing platforms based on MnSA−N3−C SAzyme is successfully built for the specific recognition of biological molecules.