•A class of MoSA–Nx–C nanozymes are designed and implemented•The peroxidase-like specificity is regulated by Mo–Nx coordination numbers•MoSA–N3–C single-atom nanozyme has superior exclusive activity•The mechanism coordination-number-dependent POD-like elucidated Nanozymes, which nanomaterials with enzyme-like characteristics, combine the advantages biocatalysts. Although stability durability th...