Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, Fine Chemical Industry Research Institute, School of Chemistry, Sun Yat-sen University, Guangzhou, 510275, P. R. China.
School of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, P. R. China.
Angew Chem Int Ed Engl. 2024 Feb 26;63(9):e202316779. doi: 10.1002/anie.202316779. Epub 2023 Dec 29.
A nanozyme with neighboring single-iron sites (Fe -SAzyme) was introduced as a bioinspired catalase mimic, featuring excellent activity under varied conditions, twice as high as that of random Fe -SAzyme and ultrahigh H O affinity as that of bioenzymes. Surprisingly, the interatomic spacing tuning between adjacent iron sites also suppressed the competitive peroxidase pathway, remarkably increasing the catalase/peroxidase selectivity up to ~6 times compared to Fe -SAzyme. This dramatically switched the catalytic activity of Fe-SAzymes from generating (i.e. Fe -SAzymes, preferably mimicking peroxidase) to scavenging ROS (i.e. Fe -SAzymes, dominantly mimicking catalase). Theoretical and experimental investigations suggested that the pairwise single-iron sites may serve as a robust molecular tweezer to efficiently trap and decompose H O into O , via cooperative hydrogen-bonding induced end-bridge adsorption. The versatile mechano-assisted in situ MOF capsulation strategy enabled facile access to neighboring M -SAzyme (M=Fe, Ir, Pt), even up to a 1000 grams scale, but with no obvious scale-up effect for both structures and performances.
引入了具有相邻单铁位点的纳米酶（Fe-SAzyme）作为仿生过氧化物酶模拟物，具有在各种条件下的优异活性，是随机 Fe-SAzyme 的两倍，与生物酶相比具有超高的 H2O2亲和力。令人惊讶的是，相邻铁位点之间的原子间间距调节还抑制了竞争过氧化物酶途径，与 Fe-SAzyme 相比，将过氧化物酶/过氧化氢酶选择性显著提高了~6 倍。这使得 Fe-SAzymes 的催化活性从产生（即 Fe-SAzymes，优选模拟过氧化物酶）显著转变为清除 ROS（即 Fe-SAzymes，主要模拟过氧化氢酶）。理论和实验研究表明，成对的单铁位点可以作为一种强大的分子夹具，通过协同氢键诱导的端桥吸附，有效地捕获和分解 H2O2 生成 O2。多功能机械辅助原位 MOF 封装策略可轻松获得相邻的 M-SAzyme（M=Fe、Ir、Pt），甚至可达 1000 克规模，但对于结构和性能都没有明显的放大效应。
