Steering N/S coordination number to accelerate catecholase-like catalysis over low-coordinated Cu site

Abstract

Modulation of coordination configuration is crucial for boosting the biomimetic catalytic activity of nanozymes, but remains challenging. Here, we found that the non-first-shell amino group in the ligand was capable of steering the N/S coordination number through remote induction to enable the formation of a low-coordinated CuN₂S₁ configuration. This endowed the resulting nanozyme (ATT-Cu) with an upshifted d-band center compared with a control nanozyme (TT-Cu) with CuN₁S₃ configuration, enhancing the adsorption capabilities of ATT-Cu for O₂ and H₂O₂ intermediates as well as its affinity for catechol. Additionally, the low-coordinated CuN₂S₁ configuration caused more charges to accumulate at the atomic Cu site, which improved the capabilities of ATT-Cu for both donating electrons to oxygen-related species and accepting electrons from catechol. As a result, this ATT-Cu nanozyme with a low-coordinated CuN₂S₁ moiety presented a faster initial oxygen reduction step, which in turn accelerated catechol oxidation, thus greatly boosting the catecholase-like activity of ATT-Cu that exceeded those of many catecholase-mimicking artificial enzymes/nanozymes with Cu–N_xO_y sites as well as those of Ce-based, Zr-based and Pt-based nanozymes.