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

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.