The Construction of a Library of Nanozyme with High Nitrogen Content for Efficient Antibacterial Applications

High catalytic efficiency is persistently pursued to generate high-performance nanozymes. Metal elements are active centers where metal-organic frameworks (MOFs) play a catalytic role. In this work, a library of MOFs-derived nanozyme is constructed based on metal salts and 1H-1,2,3-triazole (MET). Triazole has three N atoms; the intrinsic high N content is beneficial to improve the affinity of substrate H₂O₂. Meanwhile, different kinds of metals can be introduced by changing the metal salts, through which bimetallic or trimetallic MOFs can be constructed. Amongst various single-, bi-, or trimetallic MET nanozymes, MET-Fe₁Zn_0.5 nanozyme exhibits the best peroxidase (POD)-like activity. The results demonstrate that the introduction of Zn accelerates electron transfer and promotes the conversion of Fe³⁺ to Fe²⁺ in MET-Fe₁Zn_0.5 nanozyme, thus enhancing the POD-like activity of MET-Fe₁Zn_0.5 nanozyme. In particular, MET-Fe₁Zn_0.5 nanozyme exhibits excellent antibacterial efficiency. A study on antibacterial mechanism indicates that MET-Fe₁Zn_0.5 nanozyme has good adhesion to the bacterial membrane and can work in conjunction with reactive oxygen species, disrupting the oxidative phosphorylation, DNA replication, and biosynthesis of essential amino acids and cofactors within bacteria, leading to membrane damage and, eventually death of bacteria. These results suggest that a high N-coordination number MET has great potential as a new-generation nanozyme.