Selective Cleavage of Cu─N Bonds Reshaped Asymmetric Dicopper Centers and Surface Polarity for Enhanced Biomimetic...

Efficient O₂ activation at dicopper sites was often stifled by the symmetric coordination configuration of the active center and a long-overlooked interface shielding-triggered mass-transfer barrier dictated by the surface polarity of the catalyst. Herein, we reported a phosphorus-mediated chemical editing strategy to simultaneously overcome these constraints. By utilizing Hard and Soft Acids and Bases-guided selective cleavage of partial Cu─N bonds, we transformed a Cu-based precursor with the N₄Cu-CuN₄S configuration into an asymmetric low-coordinated N₂Cu-CuN₂S center. Such an asymmetric reconfiguration not only induced a pivotal reversal in surface polarity to reshape the catalytic interface from a dense cation-rich inner Helmholtz plane to a loose O₂-permeable outer Helmholtz plane, thereby facilitating O₂ diffusion and enrichment, but also upshifted the d-band center to strengthen intrinsic O₂ adsorption and polarization. This dual regulation significantly accelerated the generation of reactive oxygen species, endowing the N₂Cu-CuN₂S site with superior 4e oxidase-like activity over its N₄Cu-CuN₄S counterpart and most previous Cu-based catalysts with symmetric configurations. Leveraging the high activity and thiophilic nature of this N₂Cu-CuN₂S site, we developed a glutathione sensor with a 0.383 ppm detection limit. This work offered a selective editing avenue to engineer high-performance biomimetic catalysts with precise control over both the molecular and interfacial environment for catalysis and biosensing.