Nanozymes are promising alternatives to natural enzymes, but their use remains limited owing to poor specificity. Overcoming this and controlling the targeted enzyme-like performance of traditional nanozymes is extremely challenging due to the intrinsic structural complexity of these systems. We report theoretical design and experimental realization of a series of heterogeneous molybdenum single-atom nanozymes (named Mo_SA–N_x–C), wherein we find that the peroxidase-like specificity is well regulated by the coordination numbers of single Mo sites. The resulting Mo_SA–N₃–C catalyst shows exclusive peroxidase-like behavior. It achieves this behavior via a homolytic pathway, whereas Mo_SA–N₂–C and Mo_SA–N₄–C catalysts have a different heterolytic pathway. The mechanism of this coordination-number-dependent enzymatic specificity is attributed to geometrical structure differences and orientation relationships of the frontier molecular orbitals toward these Mo_SA–N_x–C peroxidase mimics. This study demonstrates the rational design of peroxidase-specific nanozymes and precise regulation of their enzymatic properties.

纳米酶是天然酶的有前途的替代品，但由于特异性差，其使用仍然受到限制。由于这些系统固有的结构复杂性，克服这一点并控制传统纳米酶的靶向酶样性能非常具有挑战性。我们报告了一系列异质钼单原子纳米酶（称为Mo _SA –N _x –C）的理论设计和实验实现，其中我们发现过氧化物酶样特异性受单个Mo位点的配位数很好地调节。所得的Mo _SA –N ₃ –C催化剂显示出独特的过氧化物酶样行为。它通过均溶途径实现此行为，而Mo _SA –N ₂-C和Mo _SA -N ₄ -C催化剂具有不同的杂化途径。这种依赖于配位数的酶特异性的机制归因于几何结构差异和前沿分子轨道对这些Mo _SA –N _x –C过氧化物酶模拟物的取向关系。这项研究证明了过氧化物酶特异性纳米酶的合理设计及其酶学特性的精确调节。